subsegs.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 661 行 · 第 1/2 页

 *	sub-segment.
 *	Frchain_root updated if needed.
 */

#ifndef BFD_ASSEMBLER

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  int i;

  for (i = 0; i < (int) SEG_MAXIMUM_ORDINAL; i++)
    {
      const char *s;

      s = segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#ifdef obj_segment_name
      s = obj_segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#endif
    }

#ifdef obj_add_segment
  {
    segT new_seg;
    new_seg = obj_add_segment (segname);
    subseg_set (new_seg, subseg);
    return new_seg;
  }
#else
  as_bad (_("Attempt to switch to nonexistent segment \"%s\""), segname);
  return now_seg;
#endif
}

void
subseg_set (seg, subseg)	/* begin assembly for a new sub-segment */
     register segT seg;		/* SEG_DATA or SEG_TEXT */
     register subsegT subseg;
{
#ifndef MANY_SEGMENTS
  know (seg == SEG_DATA
	|| seg == SEG_TEXT
	|| seg == SEG_BSS
	|| seg == SEG_ABSOLUTE);
#endif

  if (seg != now_seg || subseg != now_subseg)
    {				/* we just changed sub-segments */
      subseg_set_rest (seg, subseg);
    }
  mri_common_symbol = NULL;
}

#else /* BFD_ASSEMBLER */

segT
subseg_get (segname, force_new)
     const char *segname;
     int force_new;
{
  segT secptr;
  segment_info_type *seginfo;
  const char *now_seg_name = (now_seg
			      ? bfd_get_section_name (stdoutput, now_seg)
			      : 0);

  if (!force_new
      && now_seg_name
      && (now_seg_name == segname
	  || !strcmp (now_seg_name, segname)))
    return now_seg;

  if (!force_new)
    secptr = bfd_make_section_old_way (stdoutput, segname);
  else
    secptr = bfd_make_section_anyway (stdoutput, segname);

  seginfo = seg_info (secptr);
  if (! seginfo)
    {
      /* Check whether output_section is set first because secptr may
         be bfd_abs_section_ptr.  */
      if (secptr->output_section != secptr)
	secptr->output_section = secptr;
      seginfo = (segment_info_type *) xmalloc (sizeof (*seginfo));
      memset ((PTR) seginfo, 0, sizeof (*seginfo));
      seginfo->fix_root = NULL;
      seginfo->fix_tail = NULL;
      seginfo->bfd_section = secptr;
      if (secptr == bfd_abs_section_ptr)
	abs_seg_info = seginfo;
      else if (secptr == bfd_und_section_ptr)
	und_seg_info = seginfo;
      else
	bfd_set_section_userdata (stdoutput, secptr, (PTR) seginfo);
      seginfo->frchainP = NULL;
      seginfo->lineno_list_head = seginfo->lineno_list_tail = NULL;
      seginfo->sym = NULL;
      seginfo->dot = NULL;
    }
  return secptr;
}

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 0);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

/* Like subseg_new, except a new section is always created, even if
   a section with that name already exists.  */
segT
subseg_force_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 1);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

void
subseg_set (secptr, subseg)
     segT secptr;
     subsegT subseg;
{
  if (! (secptr == now_seg && subseg == now_subseg))
    subseg_set_rest (secptr, subseg);
  mri_common_symbol = NULL;
}

#ifndef obj_sec_sym_ok_for_reloc
#define obj_sec_sym_ok_for_reloc(SEC)	0
#endif

/* Get the gas information we are storing for a section.  */

segment_info_type *
seg_info (sec)
     segT sec;
{
  if (sec == bfd_abs_section_ptr)
    return abs_seg_info;
  else if (sec == bfd_und_section_ptr)
    return und_seg_info;
  else
    return (segment_info_type *) bfd_get_section_userdata (stdoutput, sec);
}

symbolS *
section_symbol (sec)
     segT sec;
{
  segment_info_type *seginfo = seg_info (sec);
  symbolS *s;

  if (seginfo == 0)
    abort ();
  if (seginfo->sym)
    return seginfo->sym;

#ifndef EMIT_SECTION_SYMBOLS
#define EMIT_SECTION_SYMBOLS 1
#endif

  if (! EMIT_SECTION_SYMBOLS
#ifdef BFD_ASSEMBLER
      || symbol_table_frozen
#endif
      )
    {
      /* Here we know it won't be going into the symbol table.  */
      s = symbol_create (sec->name, sec, 0, &zero_address_frag);
    }
  else
    {
      s = symbol_find_base (sec->name, 0);
      if (s == NULL)
	s = symbol_new (sec->name, sec, 0, &zero_address_frag);
      else
	{
	  if (S_GET_SEGMENT (s) == undefined_section)
	    {
	      S_SET_SEGMENT (s, sec);
	      symbol_set_frag (s, &zero_address_frag);
	    }
	}
    }

  S_CLEAR_EXTERNAL (s);

  /* Use the BFD section symbol, if possible.  */
  if (obj_sec_sym_ok_for_reloc (sec))
    symbol_set_bfdsym (s, sec->symbol);

  seginfo->sym = s;
  return s;
}

#endif /* BFD_ASSEMBLER */

/* Return whether the specified segment is thought to hold text.  */

#ifndef BFD_ASSEMBLER
const char * const nontext_section_names[] = {
  ".eh_frame",
  ".gcc_except_table",
#ifdef OBJ_COFF
#ifndef COFF_LONG_SECTION_NAMES
  ".eh_fram",
  ".gcc_exc",
#endif
#endif
  NULL
};
#endif /* ! BFD_ASSEMBLER */

int
subseg_text_p (sec)
     segT sec;
{
#ifdef BFD_ASSEMBLER
  return (bfd_get_section_flags (stdoutput, sec) & SEC_CODE) != 0;
#else /* ! BFD_ASSEMBLER */
  const char * const *p;

  if (sec == data_section || sec == bss_section)
    return 0;

  for (p = nontext_section_names; *p != NULL; ++p)
    {
      if (strcmp (segment_name (sec), *p) == 0)
	return 0;

#ifdef obj_segment_name
      if (strcmp (obj_segment_name (sec), *p) == 0)
	return 0;
#endif
    }

  return 1;

#endif /* ! BFD_ASSEMBLER */
}

void
subsegs_print_statistics (file)
     FILE *file;
{
  frchainS *frchp;
  fprintf (file, "frag chains:\n");
  for (frchp = frchain_root; frchp; frchp = frchp->frch_next)
    {
      int count = 0;
      fragS *fragp;

      /* If frch_subseg is non-zero, it's probably been chained onto
	 the end of a previous subsection.  Don't count it again.  */
      if (frchp->frch_subseg != 0)
	continue;

      /* Skip gas-internal sections.  */
      if (segment_name (frchp->frch_seg)[0] == '*')
	continue;

      for (fragp = frchp->frch_root; fragp; fragp = fragp->fr_next)
	{
#if 0
	  switch (fragp->fr_type)
	    {
	    case rs_fill:
	      fprintf (file, "f"); break;
	    case rs_align:
	      fprintf (file, "a"); break;
	    case rs_align_code:
	      fprintf (file, "c"); break;
	    case rs_org:
	      fprintf (file, "o"); break;
	    case rs_machine_dependent:
	      fprintf (file, "m"); break;
	    case rs_space:
	      fprintf (file, "s"); break;
	    case 0:
	      fprintf (file, "0"); break;
	    default:
	      fprintf (file, "?"); break;
	    }
#endif
	  count++;
	}
      fprintf (file, "\n");
      fprintf (file, "\t%p %-10s\t%10d frags\n", frchp,
	       segment_name (frchp->frch_seg), count);
    }
}

/* end of subsegs.c */