source: trunk/src/binutils/gas/struc-symbol.h@ 2012

/* struct_symbol.h - Internal symbol structure
   Copyright 1987, 1992, 1993, 1994, 1995, 1998, 1999, 2000, 2001
   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, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

#ifndef __struc_symbol_h__
#define __struc_symbol_h__

#ifdef BFD_ASSEMBLER
/* The BFD code wants to walk the list in both directions.  */
#undef  SYMBOLS_NEED_BACKPOINTERS
#define SYMBOLS_NEED_BACKPOINTERS
#endif

/* The information we keep for a symbol.  Note that the symbol table
   holds pointers both to this and to local_symbol structures.  See
   below.  */

struct symbol
{
#ifdef BFD_ASSEMBLER
  /* BFD symbol */
  asymbol *bsym;
#else
  /* The (4-origin) position of sy_name in the symbol table of the object
     file.  This will be 0 for (nameless) .stabd symbols.

     Not used until write_object_file() time.  */
  unsigned long sy_name_offset;

  /* What we write in .o file (if permitted).  */
  obj_symbol_type sy_symbol;

  /* The 24 bit symbol number.  Symbol numbers start at 0 and are unsigned.  */
  long sy_number;
#endif

  /* The value of the symbol.  */
  expressionS sy_value;

  /* Forwards and (optionally) backwards chain pointers.  */
  struct symbol *sy_next;
#ifdef SYMBOLS_NEED_BACKPOINTERS
  struct symbol *sy_previous;
#endif /* SYMBOLS_NEED_BACKPOINTERS */

  /* Pointer to the frag this symbol is attached to, if any.
     Otherwise, NULL.  */
  struct frag *sy_frag;

  unsigned int written : 1;
  /* Whether symbol value has been completely resolved (used during
     final pass over symbol table).  */
  unsigned int sy_resolved : 1;
  /* Whether the symbol value is currently being resolved (used to
     detect loops in symbol dependencies).  */
  unsigned int sy_resolving : 1;
  /* Whether the symbol value is used in a reloc.  This is used to
     ensure that symbols used in relocs are written out, even if they
     are local and would otherwise not be.  */
  unsigned int sy_used_in_reloc : 1;

  /* Whether the symbol is used as an operand or in an expression.
     NOTE:  Not all the backends keep this information accurate;
     backends which use this bit are responsible for setting it when
     a symbol is used in backend routines.  */
  unsigned int sy_used : 1;

  /* This is set if the symbol is defined in an MRI common section.
     We handle such sections as single common symbols, so symbols
     defined within them must be treated specially by the relocation
     routines.  */
  unsigned int sy_mri_common : 1;

#ifdef OBJ_SYMFIELD_TYPE
  OBJ_SYMFIELD_TYPE sy_obj;
#endif

#ifdef TC_SYMFIELD_TYPE
  TC_SYMFIELD_TYPE sy_tc;
#endif

#ifdef TARGET_SYMBOL_FIELDS
  TARGET_SYMBOL_FIELDS
#endif
};

#ifdef BFD_ASSEMBLER

/* A pointer in the symbol may point to either a complete symbol
   (struct symbol above) or to a local symbol (struct local_symbol
   defined here).  The symbol code can detect the case by examining
   the first field.  It is always NULL for a local symbol.

   We do this because we ordinarily only need a small amount of
   information for a local symbol.  The symbol table takes up a lot of
   space, and storing less information for a local symbol can make a
   big difference in assembler memory usage when assembling a large
   file.  */

struct local_symbol
{
  /* This pointer is always NULL to indicate that this is a local
     symbol.  */
  asymbol *lsy_marker;

  /* The symbol section.  This also serves as a flag.  If this is
     reg_section, then this symbol has been converted into a regular
     symbol, and lsy_sym points to it.  */
  segT lsy_section;

  /* The symbol name.  */
  const char *lsy_name;

  /* The symbol frag or the real symbol, depending upon the value in
     lsy_section.  If the symbol has been fully resolved, lsy_frag is
     set to NULL.  */
  union
  {
    fragS *lsy_frag;
    symbolS *lsy_sym;
  } u;

  /* The value of the symbol.  */
  valueT lsy_value;

#ifdef TC_LOCAL_SYMFIELD_TYPE
  TC_LOCAL_SYMFIELD_TYPE lsy_tc;
#endif
};

#define local_symbol_converted_p(l) ((l)->lsy_section == reg_section)
#define local_symbol_mark_converted(l) ((l)->lsy_section = reg_section)
#define local_symbol_resolved_p(l) ((l)->u.lsy_frag == NULL)
#define local_symbol_mark_resolved(l) ((l)->u.lsy_frag = NULL)
#define local_symbol_get_frag(l) ((l)->u.lsy_frag)
#define local_symbol_set_frag(l, f) ((l)->u.lsy_frag = (f))
#define local_symbol_get_real_symbol(l) ((l)->u.lsy_sym)
#define local_symbol_set_real_symbol(l, s) ((l)->u.lsy_sym = (s))

#endif /* BFD_ASSEMBLER */

#endif /* __struc_symbol_h__ */