projects / binutils.git / blame
| Commit | Line | Data |
|---|---|---|
| fecd2382 RP |
1 | /* subsegs.h -> subsegs.c |
| 2 | Copyright (C) 1987 Free Software Foundation, Inc. | |
| 3 | ||
| 4 | This file is part of GAS, the GNU Assembler. | |
| 5 | ||
| 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 1, or (at your option) | |
| 9 | any later version. | |
| 10 | ||
| 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. | |
| 15 | ||
| 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
| 19 | ||
| 20 | /* | |
| 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 | |
| 23 | * and vice versa. | |
| 24 | * | |
| 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 | |
| 31 | * can be programmed; | |
| 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. | |
| 34 | * | |
| 35 | * From each struct frchain dangles a chain of struct frags. The frags | |
| 36 | * represent code fragments, for that sub-segment, forward chained. | |
| 37 | */ | |
| 38 | ||
| 39 | struct frchain /* control building of a frag chain */ | |
| 40 | { /* FRCH = FRagment CHain control */ | |
| 41 | struct frag * frch_root; /* 1st struct frag in chain, or NULL */ | |
| 42 | struct frag * frch_last; /* last struct frag in chain, or NULL */ | |
| 43 | struct frchain * frch_next; /* next in chain of struct frchain-s */ | |
| 44 | segT frch_seg; /* SEG_TEXT or SEG_DATA. */ | |
| 45 | subsegT frch_subseg; /* subsegment number of this chain */ | |
| 46 | }; | |
| 47 | ||
| 48 | typedef struct frchain frchainS; | |
| 49 | ||
| 50 | extern frchainS * frchain_root; /* NULL means no frchains yet. */ | |
| 51 | /* all subsegments' chains hang off here */ | |
| 52 | ||
| 53 | extern frchainS * frchain_now; | |
| 54 | /* Frchain we are assembling into now */ | |
| 55 | /* That is, the current segment's frag */ | |
| 56 | /* chain, even if it contains no (complete) */ | |
| 57 | /* frags. */ | |
| 58 | ||
| 59 | extern frchainS * data0_frchainP; | |
| 60 | /* Sentinel for frchain crawling. */ | |
| 61 | /* Points to the 1st data-segment frchain. */ | |
| 62 | /* (Which is pointed to by the last text- */ | |
| 63 | /* segment frchain.) */ | |
| 64 | ||
| 65 | /* end: subsegs.h */ |