1 /* subsegs.h -> subsegs.c
2 Copyright (C) 1987, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
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 2, or (at your option)
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.
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
18 the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 * For every sub-segment the user mentions in the ASsembler program,
22 * we make one struct frchain. Each sub-segment has exactly one struct frchain
25 * Struct frchain's are forward chained (in ascending order of sub-segment
26 * code number). The chain runs through frch_next of each subsegment.
27 * This makes it hard to find a subsegment's frags
28 * if programmer uses a lot of them. Most programs only use text0 and
29 * data0, so they don't suffer. At least this way:
30 * (1) There are no "arbitrary" restrictions on how many subsegments
32 * (2) Subsegments' frchain-s are (later) chained together in the order in
33 * which they are emitted for object file viz text then data.
35 * From each struct frchain dangles a chain of struct frags. The frags
36 * represent code fragments, for that sub-segment, forward chained.
41 struct frchain /* control building of a frag chain */
42 { /* FRCH = FRagment CHain control */
43 struct frag *frch_root; /* 1st struct frag in chain, or NULL */
44 struct frag *frch_last; /* last struct frag in chain, or NULL */
45 struct frchain *frch_next; /* next in chain of struct frchain-s */
46 segT frch_seg; /* SEG_TEXT or SEG_DATA. */
47 subsegT frch_subseg; /* subsegment number of this chain */
49 fixS *fix_root; /* Root of fixups for this subsegment. */
50 fixS *fix_tail; /* Last fixup for this subsegment. */
52 struct obstack frch_obstack; /* for objects in this frag chain */
53 fragS *frch_frag_now; /* frag_now for this subsegment */
56 typedef struct frchain frchainS;
58 /* All subsegments' chains hang off here. NULL means no frchains yet. */
59 extern frchainS *frchain_root;
61 /* Frchain we are assembling into now. That is, the current segment's
62 frag chain, even if it contains no (complete) frags. */
63 extern frchainS *frchain_now;
69 unsigned int hadone : 1;
71 /* This field is set if this is a .bss section which does not really
72 have any contents. Once upon a time a .bss section did not have
73 any frags, but that is no longer true. This field prevent the
74 SEC_HAS_CONTENTS flag from being set for the section even if
80 /* Fixups for this segment. If BFD_ASSEMBLER, this is only valid
81 after the frchains are run together. */
85 #if defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
86 struct internal_scnhdr scnhdr;
87 enum linkonce_type linkonce;
93 struct lineno_list *lineno_list_head;
94 struct lineno_list *lineno_list_tail;
97 /* Which BFD section does this gas segment correspond to? */
98 asection *bfd_section;
100 /* NULL, or pointer to the gas symbol that is the section symbol for
101 this section. sym->bsym and bfd_section->symbol should be the same. */
107 /* Current size of section holding stabs strings. */
108 unsigned long stab_string_size;
109 /* Initial frag for ELF. */
114 #ifdef NEED_LITERAL_POOL
115 unsigned long literal_pool_size;
118 #ifdef TC_SEGMENT_INFO_TYPE
119 TC_SEGMENT_INFO_TYPE tc_segment_info_data;
125 extern segment_info_type *seg_info PARAMS ((segT));
126 extern symbolS *section_symbol PARAMS ((segT));
128 #else /* ! BFD_ASSEMBLER */
132 extern segment_info_type segment_info[];
134 #define seg_info(SEC) (&segment_info[SEC])
138 /* Sentinel for frchain crawling. Points to the 1st data-segment
139 frchain. (Which is pointed to by the last text-segment frchain.) */
140 extern frchainS *data0_frchainP;
141 extern frchainS *bss0_frchainP;
143 /* Dummy so stuff can compile. Should never be used. */
144 struct seg_info_trash {
146 unsigned stab_string_size : 1;
150 #define seg_info(S) (abort (), (struct seg_info_trash *) 0)
154 #endif /* ! BFD_ASSEMBLER */
156 extern void subsegs_print_statistics PARAMS ((FILE *));
158 /* end of subsegs.h */