path: root/gas/config/obj-elf.c

/* ELF object file format
   Copyright (C) 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. */

#include "as.h"
#include "subsegs.h"
#include "obstack.h"

#ifdef ECOFF_DEBUGGING
#include "ecoff.h"
#endif

static int obj_elf_write_symbol_p PARAMS ((symbolS *sym));

#ifdef ECOFF_DEBUGGING
static boolean elf_get_extr PARAMS ((asymbol *, EXTR *));
static void elf_set_index PARAMS ((asymbol *, bfd_size_type));
#endif

static void obj_elf_line PARAMS ((int));
void obj_elf_version PARAMS ((int));
static void obj_elf_size PARAMS ((int));
static void obj_elf_type PARAMS ((int));
static void obj_elf_ident PARAMS ((int));
static void obj_elf_weak PARAMS ((int));
static void obj_elf_local PARAMS ((int));
static void obj_elf_common PARAMS ((int));
static void obj_elf_data PARAMS ((int));
static void obj_elf_text PARAMS ((int));

const pseudo_typeS obj_pseudo_table[] =
{
  {"comm", obj_elf_common, 0},
  {"ident", obj_elf_ident, 0},
  {"local", obj_elf_local, 0},
  {"previous", obj_elf_previous, 0},
  {"section", obj_elf_section, 0},
  {"size", obj_elf_size, 0},
  {"type", obj_elf_type, 0},
  {"version", obj_elf_version, 0},
  {"weak", obj_elf_weak, 0},

/* These are used for stabs-in-elf configurations.  */
  {"line", obj_elf_line, 0},

  /* These are used for dwarf. */
  {"2byte", cons, 2},
  {"4byte", cons, 4},
  {"8byte", cons, 8},

  /* We need to trap the section changing calls to handle .previous.  */
  {"data", obj_elf_data, 0},
  {"text", obj_elf_text, 0},

#ifdef ECOFF_DEBUGGING
  /* COFF style debugging information for ECOFF. .ln is not used; .loc
     is used instead.  */
  { "def",	ecoff_directive_def,	0 },
  { "dim",	ecoff_directive_dim,	0 },
  { "endef",	ecoff_directive_endef,	0 },
  { "file",	ecoff_directive_file,	0 },
  { "scl",	ecoff_directive_scl,	0 },
  { "tag",	ecoff_directive_tag,	0 },
  { "val",	ecoff_directive_val,	0 },

  /* COFF debugging requires pseudo-ops .size and .type, but ELF
     already has meanings for those.  We use .esize and .etype
     instead.  These are only generated by gcc anyhow.  */
  { "esize",	ecoff_directive_size,	0 },
  { "etype",	ecoff_directive_type,	0 },

  /* ECOFF specific debugging information.  */
  { "begin",	ecoff_directive_begin,	0 },
  { "bend",	ecoff_directive_bend,	0 },
  { "end",	ecoff_directive_end,	0 },
  { "ent",	ecoff_directive_ent,	0 },
  { "fmask",	ecoff_directive_fmask,	0 },
  { "frame",	ecoff_directive_frame,	0 },
  { "loc",	ecoff_directive_loc,	0 },
  { "mask",	ecoff_directive_mask,	0 },

  /* These are used on Irix.  I don't know how to implement them.  */
  { "alias",	s_ignore,		0 },
  { "bgnb",	s_ignore,		0 },
  { "endb",	s_ignore,		0 },
  { "lab",	s_ignore,		0 },
  { "noalias",	s_ignore,		0 },
  { "verstamp",	s_ignore,		0 },
  { "vreg",	s_ignore,		0 },
#endif /* ECOFF_DEBUGGING */

  {NULL}			/* end sentinel */
};

#undef NO_RELOC
#include "aout/aout64.h"

void
elf_file_symbol (s)
     char *s;
{
  symbolS *sym;

  sym = symbol_new (s, absolute_section, (valueT) 0, (struct frag *) 0);
  sym->sy_frag = &zero_address_frag;
  sym->bsym->flags |= BSF_FILE;

  if (symbol_rootP != sym)
    {
      symbol_remove (sym, &symbol_rootP, &symbol_lastP);
      symbol_insert (sym, symbol_rootP, &symbol_rootP, &symbol_lastP);
#ifdef DEBUG
      verify_symbol_chain (symbol_rootP, symbol_lastP);
#endif
    }
}

static void
obj_elf_common (ignore)
     int ignore;
{
  char *name;
  char c;
  char *p;
  int temp, size;
  symbolS *symbolP;
  int have_align;

  name = input_line_pointer;
  c = get_symbol_end ();
  /* just after name is now '\0' */
  p = input_line_pointer;
  *p = c;
  SKIP_WHITESPACE ();
  if (*input_line_pointer != ',')
    {
      as_bad ("Expected comma after symbol-name");
      ignore_rest_of_line ();
      return;
    }
  input_line_pointer++;		/* skip ',' */
  if ((temp = get_absolute_expression ()) < 0)
    {
      as_bad (".COMMon length (%d.) <0! Ignored.", temp);
      ignore_rest_of_line ();
      return;
    }
  size = temp;
  *p = 0;
  symbolP = symbol_find_or_make (name);
  *p = c;
  if (S_IS_DEFINED (symbolP))
    {
      as_bad ("Ignoring attempt to re-define symbol");
      ignore_rest_of_line ();
      return;
    }
  if (S_GET_VALUE (symbolP) != 0)
    {
      if (S_GET_VALUE (symbolP) != size)
	{
	  as_warn ("Length of .comm \"%s\" is already %ld. Not changed to %d.",
		   S_GET_NAME (symbolP), (long) S_GET_VALUE (symbolP), size);
	}
    }
  know (symbolP->sy_frag == &zero_address_frag);
  if (*input_line_pointer != ',')
    have_align = 0;
  else
    {
      have_align = 1;
      input_line_pointer++;
      SKIP_WHITESPACE ();
    }
  if (! have_align || *input_line_pointer != '"')
    {
      if (! have_align)
	temp = 0;
      else
	{
	  temp = get_absolute_expression ();
	  if (temp < 0)
	    {
	      temp = 0;
	      as_warn ("Common alignment negative; 0 assumed");
	    }
	}
      if (symbolP->local)
	{
	  segT old_sec;
	  int old_subsec;
	  char *pfrag;
	  int align;

	/* allocate_bss: */
	  old_sec = now_seg;
	  old_subsec = now_subseg;
	  align = temp;
	  record_alignment (bss_section, align);
	  subseg_set (bss_section, 0);
	  if (align)
	    frag_align (align, 0);
	  if (S_GET_SEGMENT (symbolP) == bss_section)
	    symbolP->sy_frag->fr_symbol = 0;
	  symbolP->sy_frag = frag_now;
	  pfrag = frag_var (rs_org, 1, 1, (relax_substateT) 0, symbolP, size,
			    (char *) 0);
	  *pfrag = 0;
	  S_SET_SEGMENT (symbolP, bss_section);
	  S_CLEAR_EXTERNAL (symbolP);
	  subseg_set (old_sec, old_subsec);
	}
      else
	{
	allocate_common:
	  S_SET_VALUE (symbolP, (valueT) size);
	  S_SET_EXTERNAL (symbolP);
	  /* should be common, but this is how gas does it for now */
	  S_SET_SEGMENT (symbolP, &bfd_und_section);
	}
    }
  else
    {
      input_line_pointer++;
      /* @@ Some use the dot, some don't.  Can we get some consistency??  */
      if (*input_line_pointer == '.')
	input_line_pointer++;
      /* @@ Some say data, some say bss.  */
      if (strncmp (input_line_pointer, "bss\"", 4)
	  && strncmp (input_line_pointer, "data\"", 5))
	{
	  while (*--input_line_pointer != '"')
	    ;
	  input_line_pointer--;
	  goto bad_common_segment;
	}
      while (*input_line_pointer++ != '"')
	;
      goto allocate_common;
    }
  demand_empty_rest_of_line ();
  return;

  {
  bad_common_segment:
    p = input_line_pointer;
    while (*p && *p != '\n')
      p++;
    c = *p;
    *p = '\0';
    as_bad ("bad .common segment %s", input_line_pointer + 1);
    *p = c;
    input_line_pointer = p;
    ignore_rest_of_line ();
    return;
  }
}

static void 
obj_elf_local (ignore)
     int ignore;
{
  char *name;
  int c;
  symbolS *symbolP;

  do
    {
      name = input_line_pointer;
      c = get_symbol_end ();
      symbolP = symbol_find_or_make (name);
      *input_line_pointer = c;
      SKIP_WHITESPACE ();
      S_CLEAR_EXTERNAL (symbolP);
      symbolP->local = 1;
      if (c == ',')
	{
	  input_line_pointer++;
	  SKIP_WHITESPACE ();
	  if (*input_line_pointer == '\n')
	    c = '\n';
	}
    }
  while (c == ',');
  demand_empty_rest_of_line ();
}

static void 
obj_elf_weak (ignore)
     int ignore;
{
  char *name;
  int c;
  symbolS *symbolP;

  do
    {
      name = input_line_pointer;
      c = get_symbol_end ();
      symbolP = symbol_find_or_make (name);
      *input_line_pointer = c;
      SKIP_WHITESPACE ();
      S_SET_WEAK (symbolP);
      symbolP->local = 1;
      if (c == ',')
	{
	  input_line_pointer++;
	  SKIP_WHITESPACE ();
	  if (*input_line_pointer == '\n')
	    c = '\n';
	}
    }
  while (c == ',');
  demand_empty_rest_of_line ();
}

static segT previous_section;
static int previous_subsection;

/* Handle the .section pseudo-op.  This code supports two different
   syntaxes.  

   The first is found on Solaris, and looks like
       .section ".sec1",#alloc,#execinstr,#write
   Here the names after '#' are the SHF_* flags to turn on for the
   section.  I'm not sure how it determines the SHT_* type (BFD
   doesn't really give us control over the type, anyhow).

   The second format is found on UnixWare, and probably most SVR4
   machines, and looks like
       .section .sec1,"a",@progbits
   The quoted string may contain any combination of a, w, x, and
   represents the SHF_* flags to turn on for the section.  The string
   beginning with '@' can be progbits or nobits.  There should be
   other possibilities, but I don't know what they are.  In any case,
   BFD doesn't really let us set the section type.  */

void
obj_elf_section (xxx)
     int xxx;
{
  char *string;
  int new_sec;
  segT sec;
  flagword flags;

  /* Get name of section.  */
  SKIP_WHITESPACE ();
  if (*input_line_pointer == '"')
    {
      string = demand_copy_C_string (&xxx);
      if (string == NULL)
	{
	  ignore_rest_of_line ();
	  return;
	}
    }
  else
    {
      char *p = input_line_pointer;
      char c;
      while (0 == strchr ("\n\t,; ", *p))
	p++;
      if (p == input_line_pointer)
	{
	  as_warn ("Missing section name");
	  ignore_rest_of_line ();
	  return;
	}
      c = *p;
      *p = 0;
      string = xmalloc ((unsigned long) (p - input_line_pointer + 1));
      strcpy (string, input_line_pointer);
      *p = c;
      input_line_pointer = p;
    }

  /* Switch to the section, creating it if necessary.  */
  previous_section = now_seg;
  previous_subsection = now_subseg;

  new_sec = bfd_get_section_by_name (stdoutput, string) == NULL;
  sec = subseg_new (string, 0);

  /* If this section already existed, we don't bother to change the
     flag values.  */
  if (! new_sec)
    {
      while (! is_end_of_line[(unsigned char) *input_line_pointer])
	++input_line_pointer;
      ++input_line_pointer;
      return;
    }

  SKIP_WHITESPACE ();
  if (*input_line_pointer != ',')
    {
      /* No flags given.  Guess at some useful defaults.  */
      if (strcmp (string, ".data") == 0
	  || strcmp (string, ".data1") == 0
	  || strcmp (string, ".sdata") == 0
	  || strcmp (string, ".rodata") == 0
	  || strcmp (string, ".rodata1") == 0)
	flags = SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_RELOC | SEC_DATA;
      else if (strcmp (string, ".text") == 0
	       || strcmp (string, ".init") == 0
	       || strcmp (string, ".fini") == 0)
	flags = SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_RELOC | SEC_CODE;
      else if (strcmp (string, ".bss") == 0
	       || strcmp (string, ".sbss") == 0)
	flags = SEC_ALLOC;
      else
	flags = SEC_RELOC;
    }
  else
    {
      /* Skip the comma.  */
      ++input_line_pointer;

      SKIP_WHITESPACE ();
      if (*input_line_pointer == '"')
	{
	  /* Pick up a string with a combination of a, w, x.  */
	  flags = SEC_READONLY | SEC_RELOC;
	  ++input_line_pointer;
	  while (*input_line_pointer != '"')
	    {
	      switch (*input_line_pointer)
		{
		case 'a':
		  flags |= SEC_ALLOC | SEC_LOAD;
		  break;
		case 'w':
		  flags &=~ SEC_READONLY;
		  break;
		case 'x':
		  flags |= SEC_CODE;
		  break;
		default:
		  as_warn ("Bad .section directive: want a,w,x in string");
		  ignore_rest_of_line ();
		  return;
		}
	      ++input_line_pointer;
	    }

	  /* Skip the closing quote.  */
	  ++input_line_pointer;

	  SKIP_WHITESPACE ();
	  if (*input_line_pointer == ',')
	    {
	      ++input_line_pointer;
	      SKIP_WHITESPACE ();
	      if (*input_line_pointer == '@')
		{
		  ++input_line_pointer;
		  if (strncmp (input_line_pointer, "progbits",
			       sizeof "progbits" - 1) == 0)
		    {
		      flags |= SEC_ALLOC | SEC_LOAD;
		      input_line_pointer += sizeof "progbits" - 1;
		    }
		  else if (strncmp (input_line_pointer, "nobits",
				    sizeof "nobits" - 1) == 0)
		    {
		      flags &=~ SEC_LOAD;
		      input_line_pointer += sizeof "nobits" - 1;
		    }
		  else
		    {
		      as_warn ("Unrecognized section type");
		      ignore_rest_of_line ();
		    }
		}
	    }
	}
      else
	{
	  flags = SEC_READONLY | SEC_RELOC;
	  do
	    {
	      SKIP_WHITESPACE ();
	      if (*input_line_pointer != '#')
		{
		  as_warn ("Bad .section directive");
		  ignore_rest_of_line ();
		  return;
		}
	      ++input_line_pointer;
	      if (strncmp (input_line_pointer, "write",
			   sizeof "write" - 1) == 0)
		{
		  flags &=~ SEC_READONLY;
		  input_line_pointer += sizeof "write" - 1;
		}
	      else if (strncmp (input_line_pointer, "alloc",
				sizeof "alloc" - 1) == 0)
		{
		  flags |= SEC_ALLOC | SEC_LOAD;
		  input_line_pointer += sizeof "alloc" - 1;
		}
	      else if (strncmp (input_line_pointer, "execinstr",
				sizeof "execinstr" - 1) == 0)
		{
		  flags |= SEC_CODE;
		  input_line_pointer += sizeof "execinstr" - 1;
		}
	      else
		{
		  as_warn ("Unrecognized section attribute");
		  ignore_rest_of_line ();
		  return;
		}
	      SKIP_WHITESPACE ();
	    }
	  while (*input_line_pointer++ == ',');
	  --input_line_pointer;
	}
    }

  bfd_set_section_flags (stdoutput, sec, flags);

  demand_empty_rest_of_line ();
}

/* Change to the .data section.  */

static void
obj_elf_data (i)
     int i;
{
  previous_section = now_seg;
  previous_subsection = now_subseg;
  s_data (i);
}

/* Change to the .text section.  */

static void
obj_elf_text (i)
     int i;
{
  previous_section = now_seg;
  previous_subsection = now_subseg;
  s_text (i);
}

void
obj_elf_previous (ignore)
     int ignore;
{
  if (previous_section == 0)
    {
      as_bad (".previous without corresponding .section; ignored");
      return;
    }
  subseg_set (previous_section, previous_subsection);
  previous_section = 0;
}

static int
obj_elf_write_symbol_p (sym)
     symbolS *sym;
{
  /* If this is a local symbol, are there any relocations for which
     need this symbol? */

  /* To find this out, we examine all relocations in all bfd sections
     that have relocations.  If there is one that references this
     symbol, we need to keep this symbol.  In this case, we return a
     true status.  In all other cases, we return a false status. */

  if (S_IS_LOCAL (sym))
    {
      asymbol *bsym = sym->bsym;
      bfd *abfd = bsym->the_bfd;
      asection *bsec;

      for (bsec = abfd->sections; bsec; bsec = bsec->next)
	{
	  struct reloc_cache_entry **rlocs = bsec->orelocation;
	  int rcnt = bsec->reloc_count;

	  if (rlocs)
	    {
	      int i;

	      for (i = 0; i < rcnt; i++)
		if (rlocs[i]->sym_ptr_ptr
		    && rlocs[i]->sym_ptr_ptr[0] == bsym)
		  return 1;
	    }
	  else
	    {
	      /* No relocations for this section.  Check the seg_info
	         structure to see if there are any fixups for this
	         section. */
	      segment_info_type *seginfo = seg_info (bsec);
	      fixS *fixp;

	      for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
		if ((fixp->fx_addsy && fixp->fx_addsy->bsym == bsym)
		    || (fixp->fx_subsy && fixp->fx_subsy->bsym == bsym))
		  return 1;
	    }
	}
    }
  return 0;
}

int
obj_elf_write_symbol (sym)
     symbolS *sym;
{
  return /* obj_elf_write_symbol_p (sym) || */ !S_IS_LOCAL (sym);
}

int
obj_elf_frob_symbol (sym, punt)
     symbolS *sym;
     int *punt;
{
#if 0 /* ?? The return value is ignored.  Only the value of *punt is
	 relevant.  */
  return obj_elf_write_symbol_p (sym);
#endif
 /* FIXME: Just return 0 until is fixed.  */
 return 0;
}

static void
obj_elf_line (ignore)
     int ignore;
{
  /* Assume delimiter is part of expression.  BSD4.2 as fails with
     delightful bug, so we are not being incompatible here. */
  new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
  demand_empty_rest_of_line ();
}

void 
obj_read_begin_hook ()
{
#ifdef ECOFF_DEBUGGING
  ecoff_read_begin_hook ();
#endif
}

void 
obj_symbol_new_hook (symbolP)
     symbolS *symbolP;
{
#if 0 /* BFD already takes care of this */
  elf32_symbol_type *esym = (elf32_symbol_type *) symbolP;

  /* There is an Elf_Internal_Sym and an Elf_External_Sym.  For now,
     just zero them out.  */

  bzero ((char *) &esym->internal_elf_sym, sizeof (esym->internal_elf_sym));
  bzero ((char *) &esym->native_elf_sym, sizeof (esym->native_elf_sym));
  bzero ((char *) &esym->tc_data, sizeof (esym->tc_data));
#endif
#ifdef ECOFF_DEBUGGING
  ecoff_symbol_new_hook (symbolP);
#endif
}

void 
obj_elf_version (ignore)
     int ignore;
{
  char *name;
  unsigned int c;
  char ch;
  char *p;
  asection *seg = now_seg;
  subsegT subseg = now_subseg;
  Elf_Internal_Note i_note;
  Elf_External_Note e_note;
  asection *note_secp = (asection *) NULL;
  int i, len;

  SKIP_WHITESPACE ();
  if (*input_line_pointer == '\"')
    {
      ++input_line_pointer;	/* -> 1st char of string. */
      name = input_line_pointer;

      while (is_a_char (c = next_char_of_string ()))
	;
      c = *input_line_pointer;
      *input_line_pointer = '\0';
      *(input_line_pointer - 1) = '\0';
      *input_line_pointer = c;

      /* create the .note section */

      note_secp = subseg_new (".note", 0);
      bfd_set_section_flags (stdoutput,
			     note_secp,
			     SEC_HAS_CONTENTS | SEC_READONLY);

      /* process the version string */

      len = strlen (name);

      i_note.namesz = ((len + 1) + 3) & ~3; /* round this to word boundary */
      i_note.descsz = 0;	/* no description */
      i_note.type = NT_VERSION;
      p = frag_more (sizeof (e_note.namesz));
      md_number_to_chars (p, (valueT) i_note.namesz, 4);
      p = frag_more (sizeof (e_note.descsz));
      md_number_to_chars (p, (valueT) i_note.descsz, 4);
      p = frag_more (sizeof (e_note.type));
      md_number_to_chars (p, (valueT) i_note.type, 4);

      for (i = 0; i < len; i++)
	{
	  ch = *(name + i);
	  {
	    FRAG_APPEND_1_CHAR (ch);
	  }
	}
      frag_align (2, 0);

      subseg_set (seg, subseg);
    }
  else
    {
      as_bad ("Expected quoted string");
    }
  demand_empty_rest_of_line ();
}

static void
obj_elf_size (ignore)
     int ignore;
{
  char *name = input_line_pointer;
  char c = get_symbol_end ();
  char *p;
  expressionS exp;
  symbolS *sym;

  p = input_line_pointer;
  *p = c;
  SKIP_WHITESPACE ();
  if (*input_line_pointer != ',')
    {
      *p = 0;
      as_bad ("expected comma after name `%s' in .size directive", name);
      *p = c;
      ignore_rest_of_line ();
      return;
    }
  input_line_pointer++;
  expression (&exp);
  if (exp.X_op == O_absent)
    {
      as_bad ("missing expression in .size directive");
      exp.X_op = O_constant;
      exp.X_add_number = 0;
    }
  *p = 0;
  sym = symbol_find_or_make (name);
  *p = c;
  if (exp.X_op == O_constant)
    S_SET_SIZE (sym, exp.X_add_number);
  else
    {
#if 0
      static int warned;
      if (!warned)
	{
	  as_tsktsk (".size expressions not yet supported, ignored");
	  warned++;
	}
#endif
    }
  demand_empty_rest_of_line ();
}

static void
obj_elf_type (ignore)
     int ignore;
{
  char *name = input_line_pointer;
  char c = get_symbol_end ();
  char *p;
  int type = 0;
  symbolS *sym;

  p = input_line_pointer;
  *p = c;
  SKIP_WHITESPACE ();
  if (*input_line_pointer != ',')
    {
      as_bad ("expected comma after name in .type directive");
    egress:
      ignore_rest_of_line ();
      return;
    }
  input_line_pointer++;
  SKIP_WHITESPACE ();
  if (*input_line_pointer != '#' && *input_line_pointer != '@')
    {
      as_bad ("expected `#' or `@' after comma in .type directive");
      goto egress;
    }
  input_line_pointer++;
  if (!strncmp ("function", input_line_pointer, sizeof ("function") - 1))
    {
      type = BSF_FUNCTION;
      input_line_pointer += sizeof ("function") - 1;
    }
  else if (!strncmp ("object", input_line_pointer, sizeof ("object") - 1))
    {
      input_line_pointer += sizeof ("object") - 1;
    }
  else
    {
      as_bad ("unrecognized symbol type, ignored");
      goto egress;
    }
  demand_empty_rest_of_line ();
  *p = 0;
  sym = symbol_find_or_make (name);
  sym->bsym->flags |= type;
}

static void
obj_elf_ident (ignore)
     int ignore;
{
  static segT comment_section;
  segT old_section = now_seg;
  int old_subsection = now_subseg;

  if (!comment_section)
    {
      char *p;
      comment_section = subseg_new (".comment", 0);
      bfd_set_section_flags (stdoutput, comment_section,
			     SEC_READONLY | SEC_HAS_CONTENTS);
      p = frag_more (1);
      *p = 0;
    }
  else
    subseg_set (comment_section, 0);
  stringer (1);
  subseg_set (old_section, old_subsection);
}

/* The first entry in a .stabs section is special.  */

void
obj_elf_init_stab_section (seg)
     segT seg;
{
  char *file;
  char *p;
  char *stabstr_name;
  unsigned int stroff;

  /* Force the section to align to a longword boundary.  Without this,
     UnixWare ar crashes.  */
  bfd_set_section_alignment (stdoutput, seg, 2);

  p = frag_more (12);
  as_where (&file, (unsigned int *) NULL);
  stabstr_name = (char *) alloca (strlen (segment_name (seg)) + 4);
  strcpy (stabstr_name, segment_name (seg));
  strcat (stabstr_name, "str");
  stroff = get_stab_string_offset (file, stabstr_name);
  know (stroff == 1);
  md_number_to_chars (p, stroff, 4);
  seg_info (seg)->stabu.p = p;
}

/* Fill in the counts in the first entry in a .stabs section.  */

static void
adjust_stab_sections (abfd, sec, xxx)
     bfd *abfd;
     asection *sec;
     PTR xxx;
{
  char *name;
  asection *strsec;
  char *p;
  int strsz, nsyms;

  if (strncmp (".stab", sec->name, 5))
    return;
  if (!strcmp ("str", sec->name + strlen (sec->name) - 3))
    return;

  name = (char *) alloca (strlen (sec->name) + 4);
  strcpy (name, sec->name);
  strcat (name, "str");
  strsec = bfd_get_section_by_name (abfd, name);
  if (strsec)
    strsz = bfd_section_size (abfd, strsec);
  else
    strsz = 0;
  nsyms = bfd_section_size (abfd, sec) / 12 - 1;

  p = seg_info (sec)->stabu.p;
  assert (p != 0);

  bfd_h_put_16 (abfd, (bfd_vma) nsyms, (bfd_byte *) p + 6);
  bfd_h_put_32 (abfd, (bfd_vma) strsz, (bfd_byte *) p + 8);
}

#ifdef ECOFF_DEBUGGING

/* This function is called by the ECOFF code.  It is supposed to
   record the external symbol information so that the backend can
   write it out correctly.  The ELF backend doesn't actually handle
   this at the moment, so we do it ourselves.  We save the information
   in the symbol.  */

void
obj_ecoff_set_ext (sym, ext)
     symbolS *sym;
     EXTR *ext;
{
  sym->bsym->udata = (PTR) ext;
}

/* This function is called by bfd_ecoff_debug_externals.  It is
   supposed to *EXT to the external symbol information, and return
   whether the symbol should be used at all.  */

static boolean
elf_get_extr (sym, ext)
     asymbol *sym;
     EXTR *ext;
{
  if (sym->udata == NULL)
    return false;
  *ext = *(EXTR *) sym->udata;
  return true;
}

/* This function is called by bfd_ecoff_debug_externals.  It has
   nothing to do for ELF.  */

/*ARGSUSED*/
static void
elf_set_index (sym, indx)
     asymbol *sym;
     bfd_size_type indx;
{
}

#endif /* ECOFF_DEBUGGING */

void 
elf_frob_file ()
{
  bfd_map_over_sections (stdoutput, adjust_stab_sections, (PTR) 0);

#ifdef elf_tc_symbol
  {
    int i;

    for (i = 0; i < stdoutput->symcount; i++)
      elf_tc_symbol (stdoutput, (PTR) (stdoutput->outsymbols[i]),
		     i + 1);
  }
#endif

#ifdef elf_tc_final_processing
  elf_tc_final_processing ();
#endif

  /* Finally, we must make any target-specific sections. */

#ifdef elf_tc_make_sections
  elf_tc_make_sections (stdoutput);
#endif

#ifdef ECOFF_DEBUGGING
  /* Generate the ECOFF debugging information.  */
  {
    const struct ecoff_debug_swap *debug_swap;
    struct ecoff_debug_info debug;
    char *buf;
    asection *sec;

    debug_swap
      = get_elf_backend_data (stdoutput)->elf_backend_ecoff_debug_swap;
    know (debug_swap != (const struct ecoff_debug_swap *) NULL);
    ecoff_build_debug (&debug.symbolic_header, &buf, debug_swap);

    /* Set up the pointers in debug.  */
#define SET(ptr, offset, type) \
    debug.ptr = (type) (buf + debug.symbolic_header.offset)

    SET (line, cbLineOffset, unsigned char *);
    SET (external_dnr, cbDnOffset, PTR);
    SET (external_pdr, cbPdOffset, PTR);
    SET (external_sym, cbSymOffset, PTR);
    SET (external_opt, cbOptOffset, PTR);
    SET (external_aux, cbAuxOffset, union aux_ext *);
    SET (ss, cbSsOffset, char *);
    SET (external_fdr, cbFdOffset, PTR);
    SET (external_rfd, cbRfdOffset, PTR);
    /* ssext and external_ext are set up just below.  */

#undef SET    

    /* Set up the external symbols.  */
    debug.ssext = debug.ssext_end = NULL;
    debug.external_ext = debug.external_ext_end = NULL;
    if (! bfd_ecoff_debug_externals (stdoutput, &debug, debug_swap, true,
				     elf_get_extr, elf_set_index))
      as_fatal ("Failed to set up debugging information: %s",
		bfd_errmsg (bfd_error));

    sec = bfd_get_section_by_name (stdoutput, ".mdebug");
    assert (sec != NULL);

    know (stdoutput->output_has_begun == false);

    /* We set the size of the section, call bfd_set_section_contents
       to force the ELF backend to allocate a file position, and then
       write out the data.  FIXME: Is this really the best way to do
       this?  */
    sec->_raw_size = bfd_ecoff_debug_size (stdoutput, &debug, debug_swap);

    if (! bfd_set_section_contents (stdoutput, sec, (PTR) NULL,
				    (file_ptr) 0, (bfd_size_type) 0))
      as_fatal ("Can't start writing .mdebug section: %s",
		bfd_errmsg (bfd_error));

    know (stdoutput->output_has_begun == true);
    know (sec->filepos != 0);

    if (! bfd_ecoff_write_debug (stdoutput, &debug, debug_swap,
				 sec->filepos))
      as_fatal ("Could not write .mdebug section: %s",
		bfd_errmsg (bfd_error));
  }
#endif /* ECOFF_DEBUGGING */
}