gas/struc-symbol.h

   1 /* struct_symbol.h - Internal symbol structure
   2    Copyright 1987, 1992, 1993, 1994, 1995, 1998, 1999, 2000, 2001, 2005,
   3    2007, 2008, 2009 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 3, 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, 51 Franklin Street - Fifth Floor, Boston, MA
  20    02110-1301, USA.  */
  21
  22 #ifndef __struc_symbol_h__
  23 #define __struc_symbol_h__
  24
  25 /* The information we keep for a symbol.  Note that the symbol table
  26    holds pointers both to this and to local_symbol structures.  See
  27    below.  */
  28
  29 struct symbol
  30 {
  31   /* BFD symbol */
  32   asymbol *bsym;
  33
  34   /* The value of the symbol.  */
  35   expressionS sy_value;
  36
  37   /* Forwards and (optionally) backwards chain pointers.  */
  38   struct symbol *sy_next;
  39   struct symbol *sy_previous;
  40
  41   /* Pointer to the frag this symbol is attached to, if any.
  42      Otherwise, NULL.  */
  43   struct frag *sy_frag;
  44
  45   unsigned int written : 1;
  46   /* Whether symbol value has been completely resolved (used during
  47      final pass over symbol table).  */
  48   unsigned int sy_resolved : 1;
  49   /* Whether the symbol value is currently being resolved (used to
  50      detect loops in symbol dependencies).  */
  51   unsigned int sy_resolving : 1;
  52   /* Whether the symbol value is used in a reloc.  This is used to
  53      ensure that symbols used in relocs are written out, even if they
  54      are local and would otherwise not be.  */
  55   unsigned int sy_used_in_reloc : 1;
  56
  57   /* Whether the symbol is used as an operand or in an expression.
  58      NOTE:  Not all the backends keep this information accurate;
  59      backends which use this bit are responsible for setting it when
  60      a symbol is used in backend routines.  */
  61   unsigned int sy_used : 1;
  62
  63   /* Whether the symbol can be re-defined.  */
  64   unsigned int sy_volatile : 1;
  65
  66   /* Whether the symbol is a forward reference.  */
  67   unsigned int sy_forward_ref : 1;
  68
  69   /* This is set if the symbol is defined in an MRI common section.
  70      We handle such sections as single common symbols, so symbols
  71      defined within them must be treated specially by the relocation
  72      routines.  */
  73   unsigned int sy_mri_common : 1;
  74
  75   /* This is set if the symbol is set with a .weakref directive.  */
  76   unsigned int sy_weakrefr : 1;
  77
  78   /* This is set when the symbol is referenced as part of a .weakref
  79      directive, but only if the symbol was not in the symbol table
  80      before.  It is cleared as soon as any direct reference to the
  81      symbol is present.  */
  82   unsigned int sy_weakrefd : 1;
  83
  84 #ifdef OBJ_SYMFIELD_TYPE
  85   OBJ_SYMFIELD_TYPE sy_obj;
  86 #endif
  87
  88 #ifdef TC_SYMFIELD_TYPE
  89   TC_SYMFIELD_TYPE sy_tc;
  90 #endif
  91
  92 #ifdef TARGET_SYMBOL_FIELDS
  93   TARGET_SYMBOL_FIELDS
  94 #endif
  95 };
  96
  97 /* A pointer in the symbol may point to either a complete symbol
  98    (struct symbol above) or to a local symbol (struct local_symbol
  99    defined here).  The symbol code can detect the case by examining
 100    the first field.  It is always NULL for a local symbol.
 101
 102    We do this because we ordinarily only need a small amount of
 103    information for a local symbol.  The symbol table takes up a lot of
 104    space, and storing less information for a local symbol can make a
 105    big difference in assembler memory usage when assembling a large
 106    file.  */
 107
 108 struct local_symbol
 109 {
 110   /* This pointer is always NULL to indicate that this is a local
 111      symbol.  */
 112   asymbol *lsy_marker;
 113
 114   /* The symbol section.  This also serves as a flag.  If this is
 115      reg_section, then this symbol has been converted into a regular
 116      symbol, and lsy_sym points to it.  */
 117   segT lsy_section;
 118
 119   /* The symbol name.  */
 120   const char *lsy_name;
 121
 122   /* The symbol frag or the real symbol, depending upon the value in
 123      lsy_section.  If the symbol has been fully resolved, lsy_frag is
 124      set to NULL.  */
 125   union
 126   {
 127     fragS *lsy_frag;
 128     symbolS *lsy_sym;
 129   } u;
 130
 131   /* The value of the symbol.  */
 132   valueT lsy_value;
 133
 134 #ifdef TC_LOCAL_SYMFIELD_TYPE
 135   TC_LOCAL_SYMFIELD_TYPE lsy_tc;
 136 #endif
 137 };
 138
 139 #define local_symbol_converted_p(l) ((l)->lsy_section == reg_section)
 140 #define local_symbol_mark_converted(l) ((l)->lsy_section = reg_section)
 141 #define local_symbol_resolved_p(l) ((l)->u.lsy_frag == NULL)
 142 #define local_symbol_mark_resolved(l) ((l)->u.lsy_frag = NULL)
 143 #define local_symbol_get_frag(l) ((l)->u.lsy_frag)
 144 #define local_symbol_set_frag(l, f) ((l)->u.lsy_frag = (f))
 145 #define local_symbol_get_real_symbol(l) ((l)->u.lsy_sym)
 146 #define local_symbol_set_real_symbol(l, s) ((l)->u.lsy_sym = (s))
 147
 148 #endif /* __struc_symbol_h__ */