| 1 | /* subsegs.h -> subsegs.c |
| 2 | |
| 3 | Copyright (C) 1987, 1992, 1993, 1994 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GAS, the GNU Assembler. |
| 6 | |
| 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) |
| 10 | any later version. |
| 11 | |
| 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. |
| 16 | |
| 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | /* |
| 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 |
| 24 | * and vice versa. |
| 25 | * |
| 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 |
| 32 | * can be programmed; |
| 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. |
| 35 | * |
| 36 | * From each struct frchain dangles a chain of struct frags. The frags |
| 37 | * represent code fragments, for that sub-segment, forward chained. |
| 38 | */ |
| 39 | |
| 40 | #include "obstack.h" |
| 41 | |
| 42 | struct frchain /* control building of a frag chain */ |
| 43 | { /* FRCH = FRagment CHain control */ |
| 44 | struct frag *frch_root; /* 1st struct frag in chain, or NULL */ |
| 45 | struct frag *frch_last; /* last struct frag in chain, or NULL */ |
| 46 | struct frchain *frch_next; /* next in chain of struct frchain-s */ |
| 47 | segT frch_seg; /* SEG_TEXT or SEG_DATA. */ |
| 48 | subsegT frch_subseg; /* subsegment number of this chain */ |
| 49 | #ifdef BFD_ASSEMBLER |
| 50 | fixS *fix_root; /* Root of fixups for this subsegment. */ |
| 51 | fixS *fix_tail; /* Last fixup for this subsegment. */ |
| 52 | #endif |
| 53 | struct obstack frch_obstack; /* for objects in this frag chain */ |
| 54 | fragS *frch_frag_now; /* frag_now for this subsegment */ |
| 55 | }; |
| 56 | |
| 57 | typedef struct frchain frchainS; |
| 58 | |
| 59 | /* All subsegments' chains hang off here. NULL means no frchains yet. */ |
| 60 | extern frchainS *frchain_root; |
| 61 | |
| 62 | /* Frchain we are assembling into now. That is, the current segment's |
| 63 | frag chain, even if it contains no (complete) frags. */ |
| 64 | extern frchainS *frchain_now; |
| 65 | |
| 66 | |
| 67 | typedef struct |
| 68 | { |
| 69 | frchainS *frchainP; |
| 70 | unsigned int hadone : 1; |
| 71 | |
| 72 | /* This field is set if this is a .bss section which does not really |
| 73 | have any contents. Once upon a time a .bss section did not have |
| 74 | any frags, but that is no longer true. This field prevent the |
| 75 | SEC_HAS_CONTENTS flag from being set for the section even if |
| 76 | there are frags. */ |
| 77 | unsigned int bss : 1; |
| 78 | |
| 79 | int user_stuff; |
| 80 | |
| 81 | /* Fixups for this segment. If BFD_ASSEMBLER, this is only valid |
| 82 | after the frchains are run together. */ |
| 83 | fixS *fix_root; |
| 84 | fixS *fix_tail; |
| 85 | |
| 86 | #if defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) |
| 87 | struct internal_scnhdr scnhdr; |
| 88 | enum linkonce_type linkonce; |
| 89 | const char *name; |
| 90 | #endif |
| 91 | |
| 92 | symbolS *dot; |
| 93 | |
| 94 | struct lineno_list *lineno_list_head; |
| 95 | struct lineno_list *lineno_list_tail; |
| 96 | |
| 97 | #ifdef BFD_ASSEMBLER |
| 98 | /* Which BFD section does this gas segment correspond to? */ |
| 99 | asection *bfd_section; |
| 100 | |
| 101 | /* NULL, or pointer to the gas symbol that is the section symbol for |
| 102 | this section. sym->bsym and bfd_section->symbol should be the same. */ |
| 103 | symbolS *sym; |
| 104 | #endif |
| 105 | |
| 106 | union |
| 107 | { |
| 108 | /* Current size of section holding stabs strings. */ |
| 109 | unsigned long stab_string_size; |
| 110 | /* Initial frag for ELF. */ |
| 111 | char *p; |
| 112 | } |
| 113 | stabu; |
| 114 | |
| 115 | #ifdef NEED_LITERAL_POOL |
| 116 | unsigned long literal_pool_size; |
| 117 | #endif |
| 118 | } segment_info_type; |
| 119 | |
| 120 | #ifdef BFD_ASSEMBLER |
| 121 | |
| 122 | extern segment_info_type *seg_info PARAMS ((segT)); |
| 123 | extern symbolS *section_symbol PARAMS ((segT)); |
| 124 | |
| 125 | #else /* ! BFD_ASSEMBLER */ |
| 126 | |
| 127 | #ifdef MANY_SEGMENTS |
| 128 | |
| 129 | extern segment_info_type segment_info[]; |
| 130 | |
| 131 | #define seg_info(SEC) (&segment_info[SEC]) |
| 132 | |
| 133 | #else |
| 134 | |
| 135 | /* Sentinel for frchain crawling. Points to the 1st data-segment |
| 136 | frchain. (Which is pointed to by the last text-segment frchain.) */ |
| 137 | extern frchainS *data0_frchainP; |
| 138 | extern frchainS *bss0_frchainP; |
| 139 | |
| 140 | /* Dummy so stuff can compile. Should never be used. */ |
| 141 | struct seg_info_trash { |
| 142 | struct { |
| 143 | unsigned stab_string_size : 1; |
| 144 | } stabu; |
| 145 | unsigned hadone : 1; |
| 146 | }; |
| 147 | #define seg_info(S) (abort (), (struct seg_info_trash *) 0) |
| 148 | |
| 149 | #endif |
| 150 | |
| 151 | #endif /* ! BFD_ASSEMBLER */ |
| 152 | |
| 153 | /* end of subsegs.h */ |