gas/struc-symbol.h

   1 /* struct_symbol.h - Internal symbol structure
   2    Copyright 1987, 1992, 1993, 1994, 1995, 1998, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GAS, the GNU Assembler.
   6
   7    GAS is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    GAS is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GAS; see the file COPYING.  If not, write to the Free
  19    Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20    02111-1307, USA.  */
  21
  22 #ifndef __struc_symbol_h__
  23 #define __struc_symbol_h__
  24
  25 #ifdef BFD_ASSEMBLER
  26 /* The BFD code wants to walk the list in both directions.  */
  27 #undef  SYMBOLS_NEED_BACKPOINTERS
  28 #define SYMBOLS_NEED_BACKPOINTERS
  29 #endif
  30
  31 /* The information we keep for a symbol.  Note that the symbol table
  32    holds pointers both to this and to local_symbol structures.  See
  33    below.  */
  34
  35 struct symbol
  36 {
  37 #ifdef BFD_ASSEMBLER
  38   /* BFD symbol */
  39   asymbol *bsym;
  40 #else
  41   /* The (4-origin) position of sy_name in the symbol table of the object
  42      file.  This will be 0 for (nameless) .stabd symbols.
  43
  44      Not used until write_object_file() time.  */
  45   unsigned long sy_name_offset;
  46
  47   /* What we write in .o file (if permitted).  */
  48   obj_symbol_type sy_symbol;
  49
  50   /* The 24 bit symbol number.  Symbol numbers start at 0 and are unsigned.  */
  51   long sy_number;
  52 #endif
  53
  54   /* The value of the symbol.  */
  55   expressionS sy_value;
  56
  57   /* Forwards and (optionally) backwards chain pointers.  */
  58   struct symbol *sy_next;
  59 #ifdef SYMBOLS_NEED_BACKPOINTERS
  60   struct symbol *sy_previous;
  61 #endif /* SYMBOLS_NEED_BACKPOINTERS */
  62
  63   /* Pointer to the frag this symbol is attached to, if any.
  64      Otherwise, NULL.  */
  65   struct frag *sy_frag;
  66
  67   unsigned int written : 1;
  68   /* Whether symbol value has been completely resolved (used during
  69      final pass over symbol table).  */
  70   unsigned int sy_resolved : 1;
  71   /* Whether the symbol value is currently being resolved (used to
  72      detect loops in symbol dependencies).  */
  73   unsigned int sy_resolving : 1;
  74   /* Whether the symbol value is used in a reloc.  This is used to
  75      ensure that symbols used in relocs are written out, even if they
  76      are local and would otherwise not be.  */
  77   unsigned int sy_used_in_reloc : 1;
  78
  79   /* Whether the symbol is used as an operand or in an expression.
  80      NOTE:  Not all the backends keep this information accurate;
  81      backends which use this bit are responsible for setting it when
  82      a symbol is used in backend routines.  */
  83   unsigned int sy_used : 1;
  84
  85   /* This is set if the symbol is defined in an MRI common section.
  86      We handle such sections as single common symbols, so symbols
  87      defined within them must be treated specially by the relocation
  88      routines.  */
  89   unsigned int sy_mri_common : 1;
  90
  91 #ifdef OBJ_SYMFIELD_TYPE
  92   OBJ_SYMFIELD_TYPE sy_obj;
  93 #endif
  94
  95 #ifdef TC_SYMFIELD_TYPE
  96   TC_SYMFIELD_TYPE sy_tc;
  97 #endif
  98
  99 #ifdef TARGET_SYMBOL_FIELDS
 100   TARGET_SYMBOL_FIELDS
 101 #endif
 102 };
 103
 104 #ifdef BFD_ASSEMBLER
 105
 106 /* A pointer in the symbol may point to either a complete symbol
 107    (struct symbol above) or to a local symbol (struct local_symbol
 108    defined here).  The symbol code can detect the case by examining
 109    the first field.  It is always NULL for a local symbol.
 110
 111    We do this because we ordinarily only need a small amount of
 112    information for a local symbol.  The symbol table takes up a lot of
 113    space, and storing less information for a local symbol can make a
 114    big difference in assembler memory usage when assembling a large
 115    file.  */
 116
 117 struct local_symbol
 118 {
 119   /* This pointer is always NULL to indicate that this is a local
 120      symbol.  */
 121   asymbol *lsy_marker;
 122
 123   /* The symbol section.  This also serves as a flag.  If this is
 124      reg_section, then this symbol has been converted into a regular
 125      symbol, and sy_sym points to it.  */
 126   segT lsy_section;
 127
 128   /* The symbol name.  */
 129   const char *lsy_name;
 130
 131   /* The symbol frag or the real symbol, depending upon the value in
 132      sy_section.  If the symbol has been fully resolved, lsy_frag is
 133      set to NULL.  */
 134   union
 135   {
 136     fragS *lsy_frag;
 137     symbolS *lsy_sym;
 138   } u;
 139
 140   /* The offset within the frag.  */
 141   valueT lsy_offset;
 142 };
 143
 144 #define local_symbol_converted_p(l) ((l)->lsy_section == reg_section)
 145 #define local_symbol_mark_converted(l) ((l)->lsy_section = reg_section)
 146 #define local_symbol_resolved_p(l) ((l)->u.lsy_frag == NULL)
 147 #define local_symbol_mark_resolved(l) ((l)->u.lsy_frag = NULL)
 148 #define local_symbol_get_frag(l) ((l)->u.lsy_frag)
 149 #define local_symbol_set_frag(l, f) ((l)->u.lsy_frag = (f))
 150 #define local_symbol_get_real_symbol(l) ((l)->u.lsy_sym)
 151 #define local_symbol_set_real_symbol(l, s) ((l)->u.lsy_sym = (s))
 152
 153 #endif /* BFD_ASSEMBLER */
 154
 155 #endif /* __struc_symbol_h__ */