1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
/* subsegs.h -> subsegs.c
Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000
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. */
/*
* For every sub-segment the user mentions in the ASsembler program,
* we make one struct frchain. Each sub-segment has exactly one struct frchain
* and vice versa.
*
* Struct frchain's are forward chained (in ascending order of sub-segment
* code number). The chain runs through frch_next of each subsegment.
* This makes it hard to find a subsegment's frags
* if programmer uses a lot of them. Most programs only use text0 and
* data0, so they don't suffer. At least this way:
* (1) There are no "arbitrary" restrictions on how many subsegments
* can be programmed;
* (2) Subsegments' frchain-s are (later) chained together in the order in
* which they are emitted for object file viz text then data.
*
* From each struct frchain dangles a chain of struct frags. The frags
* represent code fragments, for that sub-segment, forward chained.
*/
#include "obstack.h"
struct frchain /* control building of a frag chain */
{ /* FRCH = FRagment CHain control */
struct frag *frch_root; /* 1st struct frag in chain, or NULL */
struct frag *frch_last; /* last struct frag in chain, or NULL */
struct frchain *frch_next; /* next in chain of struct frchain-s */
segT frch_seg; /* SEG_TEXT or SEG_DATA. */
subsegT frch_subseg; /* subsegment number of this chain */
#ifdef BFD_ASSEMBLER
fixS *fix_root; /* Root of fixups for this subsegment. */
fixS *fix_tail; /* Last fixup for this subsegment. */
#endif
struct obstack frch_obstack; /* for objects in this frag chain */
fragS *frch_frag_now; /* frag_now for this subsegment */
};
typedef struct frchain frchainS;
/* All subsegments' chains hang off here. NULL means no frchains yet. */
extern frchainS *frchain_root;
/* Frchain we are assembling into now. That is, the current segment's
frag chain, even if it contains no (complete) frags. */
extern frchainS *frchain_now;
typedef struct segment_info_struct {
frchainS *frchainP;
unsigned int hadone : 1;
/* This field is set if this is a .bss section which does not really
have any contents. Once upon a time a .bss section did not have
any frags, but that is no longer true. This field prevent the
SEC_HAS_CONTENTS flag from being set for the section even if
there are frags. */
unsigned int bss : 1;
int user_stuff;
/* Fixups for this segment. If BFD_ASSEMBLER, this is only valid
after the frchains are run together. */
fixS *fix_root;
fixS *fix_tail;
#if defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
struct internal_scnhdr scnhdr;
enum linkonce_type linkonce;
const char *name;
#endif
symbolS *dot;
struct lineno_list *lineno_list_head;
struct lineno_list *lineno_list_tail;
#ifdef BFD_ASSEMBLER
/* Which BFD section does this gas segment correspond to? */
asection *bfd_section;
/* NULL, or pointer to the gas symbol that is the section symbol for
this section. sym->bsym and bfd_section->symbol should be the same. */
symbolS *sym;
#endif
union {
/* Current size of section holding stabs strings. */
unsigned long stab_string_size;
/* Initial frag for ELF. */
char *p;
}
stabu;
#ifdef NEED_LITERAL_POOL
unsigned long literal_pool_size;
#endif
#ifdef TC_SEGMENT_INFO_TYPE
TC_SEGMENT_INFO_TYPE tc_segment_info_data;
#endif
} segment_info_type;
#ifdef BFD_ASSEMBLER
extern segment_info_type *seg_info PARAMS ((segT));
extern symbolS *section_symbol PARAMS ((segT));
#else /* ! BFD_ASSEMBLER */
#ifdef MANY_SEGMENTS
extern segment_info_type segment_info[];
#define seg_info(SEC) (&segment_info[SEC])
#else
/* Sentinel for frchain crawling. Points to the 1st data-segment
frchain. (Which is pointed to by the last text-segment frchain.) */
extern frchainS *data0_frchainP;
extern frchainS *bss0_frchainP;
/* Dummy so stuff can compile. Should never be used. */
struct seg_info_trash {
struct {
unsigned stab_string_size : 1;
} stabu;
unsigned hadone : 1;
};
#define seg_info(S) (abort (), (struct seg_info_trash *) 0)
#endif
#endif /* ! BFD_ASSEMBLER */
extern void subsegs_print_statistics PARAMS ((FILE *));
|
