2007-07-26 Michael Snyder <msnyder@access-company.com>
[binutils.git] / gas / subsegs.h
blob090d25cb6fe5bab501b14aa7e8e862f162af494c
1 /* subsegs.h -> subsegs.c
2 Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2003, 2005,
3 2006, 2007 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
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.
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.
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. */
23 * For every sub-segment the user mentions in the ASsembler program,
24 * we make one struct frchain. Each sub-segment has exactly one struct frchain
25 * and vice versa.
27 * Struct frchain's are forward chained (in ascending order of sub-segment
28 * code number). The chain runs through frch_next of each subsegment.
29 * This makes it hard to find a subsegment's frags
30 * if programmer uses a lot of them. Most programs only use text0 and
31 * data0, so they don't suffer. At least this way:
32 * (1) There are no "arbitrary" restrictions on how many subsegments
33 * can be programmed;
34 * (2) Subsegments' frchain-s are (later) chained together in the order in
35 * which they are emitted for object file viz text then data.
37 * From each struct frchain dangles a chain of struct frags. The frags
38 * represent code fragments, for that sub-segment, forward chained.
41 #include "obstack.h"
43 struct frch_cfi_data;
45 struct frchain /* control building of a frag chain */
46 { /* FRCH = FRagment CHain control */
47 struct frag *frch_root; /* 1st struct frag in chain, or NULL */
48 struct frag *frch_last; /* last struct frag in chain, or NULL */
49 struct frchain *frch_next; /* next in chain of struct frchain-s */
50 subsegT frch_subseg; /* subsegment number of this chain */
51 fixS *fix_root; /* Root of fixups for this subsegment. */
52 fixS *fix_tail; /* Last fixup for this subsegment. */
53 struct obstack frch_obstack; /* for objects in this frag chain */
54 fragS *frch_frag_now; /* frag_now for this subsegment */
55 struct frch_cfi_data *frch_cfi_data;
58 typedef struct frchain frchainS;
60 /* Frchain we are assembling into now. That is, the current segment's
61 frag chain, even if it contains no (complete) frags. */
62 extern frchainS *frchain_now;
64 typedef struct segment_info_struct {
65 frchainS *frchainP;
66 unsigned int hadone : 1;
68 /* This field is set if this is a .bss section which does not really
69 have any contents. Once upon a time a .bss section did not have
70 any frags, but that is no longer true. This field prevent the
71 SEC_HAS_CONTENTS flag from being set for the section even if
72 there are frags. */
73 unsigned int bss : 1;
75 int user_stuff;
77 /* Fixups for this segment. This is only valid after the frchains
78 are run together. */
79 fixS *fix_root;
80 fixS *fix_tail;
82 symbolS *dot;
84 struct lineno_list *lineno_list_head;
85 struct lineno_list *lineno_list_tail;
87 /* Which BFD section does this gas segment correspond to? */
88 asection *bfd_section;
90 /* NULL, or pointer to the gas symbol that is the section symbol for
91 this section. sym->bsym and bfd_section->symbol should be the same. */
92 symbolS *sym;
94 union {
95 /* Current size of section holding stabs strings. */
96 unsigned long stab_string_size;
97 /* Initial frag for ELF. */
98 char *p;
100 stabu;
102 #ifdef NEED_LITERAL_POOL
103 unsigned long literal_pool_size;
104 #endif
106 #ifdef TC_SEGMENT_INFO_TYPE
107 TC_SEGMENT_INFO_TYPE tc_segment_info_data;
108 #endif
109 } segment_info_type;
112 #define seg_info(sec) \
113 ((segment_info_type *) bfd_get_section_userdata (stdoutput, sec))
115 extern symbolS *section_symbol (segT);
117 extern void subsegs_print_statistics (FILE *);