1 /* subsegs.h -> subsegs.c
3 Copyright (C) 1987, 1992 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 2, or (at your option)
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
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
22 * For every sub-segment the user mentions in the ASsembler program,
23 * we make one struct frchain. Each sub-segment has exactly one struct frchain
26 * Struct frchain's are forward chained (in ascending order of sub-segment
27 * code number). The chain runs through frch_next of each subsegment.
28 * This makes it hard to find a subsegment's frags
29 * if programmer uses a lot of them. Most programs only use text0 and
30 * data0, so they don't suffer. At least this way:
31 * (1) There are no "arbitrary" restrictions on how many subsegments
33 * (2) Subsegments' frchain-s are (later) chained together in the order in
34 * which they are emitted for object file viz text then data.
36 * From each struct frchain dangles a chain of struct frags. The frags
37 * represent code fragments, for that sub-segment, forward chained.
40 struct frchain
/* control building of a frag chain */
41 { /* FRCH = FRagment CHain control */
42 struct frag
*frch_root
; /* 1st struct frag in chain, or NULL */
43 struct frag
*frch_last
; /* last struct frag in chain, or NULL */
44 struct frchain
*frch_next
; /* next in chain of struct frchain-s */
45 segT frch_seg
; /* SEG_TEXT or SEG_DATA. */
46 subsegT frch_subseg
; /* subsegment number of this chain */
49 typedef struct frchain frchainS
;
51 /* All subsegments' chains hang off here. NULL means no frchains yet. */
52 extern frchainS
*frchain_root
;
54 /* Frchain we are assembling into now That is, the current segment's
55 frag chain, even if it contains no (complete) frags. */
56 extern frchainS
*frchain_now
;
64 /* This field is set if this is a .bss section which does not really
65 have any contents. Once upon a time a .bss section did not have
66 any frags, but that is no longer true. This field prevent the
67 SEC_HAS_CONTENTS flag from being set for the section even if
74 #if defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
75 struct internal_scnhdr scnhdr
;
79 struct lineno_list
*lineno_list_head
;
80 struct lineno_list
*lineno_list_tail
;
83 /* Which BFD section does this gas segment correspond to? */
84 asection
*bfd_section
;
86 /* NULL, or pointer to the gas symbol that is the section symbol for
87 this section. sym->bsym and bfd_section->symbol should be the same. */
93 /* Current size of section holding stabs strings. */
94 unsigned long stab_string_size
;
95 /* Initial frag for ELF. */
100 #ifdef NEED_LITERAL_POOL
101 unsigned long literal_pool_size
;
107 #define seg_info(SEC) \
108 ((segment_info_type *) bfd_get_section_userdata (stdoutput, (SEC)))
109 extern symbolS
*section_symbol
PARAMS ((segT
));
111 #else /* ! BFD_ASSEMBLER */
115 extern segment_info_type segment_info
[];
117 #define seg_info(SEC) (&segment_info[SEC])
121 /* Sentinel for frchain crawling. Points to the 1st data-segment
122 frchain. (Which is pointed to by the last text-segment frchain.) */
123 extern frchainS
*data0_frchainP
;
124 extern frchainS
*bss0_frchainP
;
128 #endif /* ! BFD_ASSEMBLER */
130 /* end of subsegs.h */