1/* struct_symbol.h - Internal symbol structure
2   Copyright (C) 1987-2017 Free Software Foundation, Inc.
3
4   This file is part of GAS, the GNU Assembler.
5
6   GAS is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3, or (at your option)
9   any later version.
10
11   GAS is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with GAS; see the file COPYING.  If not, write to the Free
18   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
19   02110-1301, USA.  */
20
21#ifndef __struc_symbol_h__
22#define __struc_symbol_h__
23
24struct symbol_flags
25{
26  /* Wether the symbol is a local_symbol.  */
27  unsigned int sy_local_symbol : 1;
28
29  /* Wether symbol has been written.  */
30  unsigned int sy_written : 1;
31
32  /* Whether symbol value has been completely resolved (used during
33     final pass over symbol table).  */
34  unsigned int sy_resolved : 1;
35
36  /* Whether the symbol value is currently being resolved (used to
37     detect loops in symbol dependencies).  */
38  unsigned int sy_resolving : 1;
39
40  /* Whether the symbol value is used in a reloc.  This is used to
41     ensure that symbols used in relocs are written out, even if they
42     are local and would otherwise not be.  */
43  unsigned int sy_used_in_reloc : 1;
44
45  /* Whether the symbol is used as an operand or in an expression.
46     NOTE:  Not all the backends keep this information accurate;
47     backends which use this bit are responsible for setting it when
48     a symbol is used in backend routines.  */
49  unsigned int sy_used : 1;
50
51  /* Whether the symbol can be re-defined.  */
52  unsigned int sy_volatile : 1;
53
54  /* Whether the symbol is a forward reference.  */
55  unsigned int sy_forward_ref : 1;
56
57  /* This is set if the symbol is defined in an MRI common section.
58     We handle such sections as single common symbols, so symbols
59     defined within them must be treated specially by the relocation
60     routines.  */
61  unsigned int sy_mri_common : 1;
62
63  /* This is set if the symbol is set with a .weakref directive.  */
64  unsigned int sy_weakrefr : 1;
65
66  /* This is set when the symbol is referenced as part of a .weakref
67     directive, but only if the symbol was not in the symbol table
68     before.  It is cleared as soon as any direct reference to the
69     symbol is present.  */
70  unsigned int sy_weakrefd : 1;
71};
72
73/* The information we keep for a symbol.  Note that the symbol table
74   holds pointers both to this and to local_symbol structures.  See
75   below.  */
76
77struct symbol
78{
79  /* Symbol flags.  */
80  struct symbol_flags sy_flags;
81
82  /* BFD symbol */
83  asymbol *bsym;
84
85  /* The value of the symbol.  */
86  expressionS sy_value;
87
88  /* Forwards and (optionally) backwards chain pointers.  */
89  struct symbol *sy_next;
90  struct symbol *sy_previous;
91
92  /* Pointer to the frag this symbol is attached to, if any.
93     Otherwise, NULL.  */
94  struct frag *sy_frag;
95
96#ifdef OBJ_SYMFIELD_TYPE
97  OBJ_SYMFIELD_TYPE sy_obj;
98#endif
99
100#ifdef TC_SYMFIELD_TYPE
101  TC_SYMFIELD_TYPE sy_tc;
102#endif
103
104#ifdef TARGET_SYMBOL_FIELDS
105  TARGET_SYMBOL_FIELDS
106#endif
107};
108
109/* A pointer in the symbol may point to either a complete symbol
110   (struct symbol above) or to a local symbol (struct local_symbol
111   defined here).  The symbol code can detect the case by examining
112   the first field.  It is always NULL for a local symbol.
113
114   We do this because we ordinarily only need a small amount of
115   information for a local symbol.  The symbol table takes up a lot of
116   space, and storing less information for a local symbol can make a
117   big difference in assembler memory usage when assembling a large
118   file.  */
119
120struct local_symbol
121{
122  /* Symbol flags.  Only sy_local_symbol and sy_resolved are relevant.  */
123  struct symbol_flags lsy_flags;
124
125  /* The symbol section.  This also serves as a flag.  If this is
126     reg_section, then this symbol has been converted into a regular
127     symbol, and lsy_sym points to it.  */
128  segT lsy_section;
129
130  /* The symbol name.  */
131  const char *lsy_name;
132
133  /* The symbol frag or the real symbol, depending upon the value in
134     lsy_section.  */
135  union
136  {
137    fragS *lsy_frag;
138    symbolS *lsy_sym;
139  } u;
140
141  /* The value of the symbol.  */
142  valueT lsy_value;
143
144#ifdef TC_LOCAL_SYMFIELD_TYPE
145  TC_LOCAL_SYMFIELD_TYPE lsy_tc;
146#endif
147};
148
149#define local_symbol_converted_p(l) ((l)->lsy_section == reg_section)
150#define local_symbol_mark_converted(l) ((l)->lsy_section = reg_section)
151#define local_symbol_resolved_p(l) ((l)->lsy_flags.sy_resolved)
152#define local_symbol_mark_resolved(l) ((l)->lsy_flags.sy_resolved = 1)
153#define local_symbol_get_frag(l) ((l)->u.lsy_frag)
154#define local_symbol_set_frag(l, f) ((l)->u.lsy_frag = (f))
155#define local_symbol_get_real_symbol(l) ((l)->u.lsy_sym)
156#define local_symbol_set_real_symbol(l, s) ((l)->u.lsy_sym = (s))
157
158#endif /* __struc_symbol_h__ */
159