/* subsegs.h -> subsegs.c
Copyright (C) 1987 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
* For every sub-segment the user mentions in the ASsembler program,
* we make one struct frchain. Each sub-segment has exactly one struct frchain
* Struct frchain's are forward chained (in ascending order of sub-segment
* code number). The chain runs through frch_next of each subsegment.
* This makes it hard to find a subsegment's frags
* if programmer uses a lot of them. Most programs only use text0 and
* data0, so they don't suffer. At least this way:
* (1) There are no "arbitrary" restrictions on how many subsegments
* (2) Subsegments' frchain-s are (later) chained together in the order in
* which they are emitted for object file viz text then data.
* From each struct frchain dangles a chain of struct frags. The frags
* represent code fragments, for that sub-segment, forward chained.
struct frchain
/* control building of a frag chain */
{ /* FRCH = FRagment CHain control */
struct frag
* frch_root
; /* 1st struct frag in chain, or NULL */
struct frag
* frch_last
; /* last struct frag in chain, or NULL */
struct frchain
* frch_next
; /* next in chain of struct frchain-s */
segT frch_seg
; /* SEG_TEXT or SEG_DATA. */
subsegT frch_subseg
; /* subsegment number of this chain */
typedef struct frchain frchainS
;
extern frchainS
* frchain_root
; /* NULL means no frchains yet. */
/* all subsegments' chains hang off here */
extern frchainS
* frchain_now
;
/* Frchain we are assembling into now */
/* That is, the current segment's frag */
/* chain, even if it contains no (complete) */
extern frchainS
* data0_frchainP
;
/* Sentinel for frchain crawling. */
/* Points to the 1st data-segment frchain. */
/* (Which is pointed to by the last text- */