struc-symbol.h revision 89857 
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
35struct 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
117struct 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 lsy_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     lsy_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 value of the symbol.  */
141  valueT lsy_value;
142
143#ifdef TC_LOCAL_SYMFIELD_TYPE
144  TC_LOCAL_SYMFIELD_TYPE lsy_tc;
145#endif
146};
147
148#define local_symbol_converted_p(l) ((l)->lsy_section == reg_section)
149#define local_symbol_mark_converted(l) ((l)->lsy_section = reg_section)
150#define local_symbol_resolved_p(l) ((l)->u.lsy_frag == NULL)
151#define local_symbol_mark_resolved(l) ((l)->u.lsy_frag = NULL)
152#define local_symbol_get_frag(l) ((l)->u.lsy_frag)
153#define local_symbol_set_frag(l, f) ((l)->u.lsy_frag = (f))
154#define local_symbol_get_real_symbol(l) ((l)->u.lsy_sym)
155#define local_symbol_set_real_symbol(l, s) ((l)->u.lsy_sym = (s))
156
157#endif /* BFD_ASSEMBLER */
158
159#endif /* __struc_symbol_h__ */
160