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/* subsegs.h -> subsegs.c
Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2003, 2005
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 2, or (at your option)
any later version.
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, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, 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
* and vice versa.
*
* 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
* can be programmed;
* (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.
*/
#include "obstack.h"
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 */
#ifdef BFD_ASSEMBLER
fixS *fix_root; /* Root of fixups for this subsegment. */
fixS *fix_tail; /* Last fixup for this subsegment. */
#endif
struct obstack frch_obstack; /* for objects in this frag chain */
fragS *frch_frag_now; /* frag_now for this subsegment */
};
typedef struct frchain frchainS;
/* All subsegments' chains hang off here. NULL means no frchains yet. */
extern frchainS *frchain_root;
/* Frchain we are assembling into now. That is, the current segment's
frag chain, even if it contains no (complete) frags. */
extern frchainS *frchain_now;
typedef struct segment_info_struct {
frchainS *frchainP;
unsigned int hadone : 1;
/* This field is set if this is a .bss section which does not really
have any contents. Once upon a time a .bss section did not have
any frags, but that is no longer true. This field prevent the
SEC_HAS_CONTENTS flag from being set for the section even if
there are frags. */
unsigned int bss : 1;
int user_stuff;
/* Fixups for this segment. If BFD_ASSEMBLER, this is only valid
after the frchains are run together. */
fixS *fix_root;
fixS *fix_tail;
#if defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
struct internal_scnhdr scnhdr;
enum linkonce_type linkonce;
const char *name;
#endif
symbolS *dot;
struct lineno_list *lineno_list_head;
struct lineno_list *lineno_list_tail;
#ifdef BFD_ASSEMBLER
/* Which BFD section does this gas segment correspond to? */
asection *bfd_section;
/* NULL, or pointer to the gas symbol that is the section symbol for
this section. sym->bsym and bfd_section->symbol should be the same. */
symbolS *sym;
#endif
union {
/* Current size of section holding stabs strings. */
unsigned long stab_string_size;
/* Initial frag for ELF. */
char *p;
}
stabu;
#ifdef NEED_LITERAL_POOL
unsigned long literal_pool_size;
#endif
#ifdef TC_SEGMENT_INFO_TYPE
TC_SEGMENT_INFO_TYPE tc_segment_info_data;
#endif
} segment_info_type;
#ifdef BFD_ASSEMBLER
extern segment_info_type *seg_info (segT);
extern symbolS *section_symbol (segT);
#else /* ! BFD_ASSEMBLER */
#ifdef MANY_SEGMENTS
extern segment_info_type segment_info[];
#define seg_info(SEC) (&segment_info[SEC])
#else
/* Sentinel for frchain crawling. Points to the 1st data-segment
frchain. (Which is pointed to by the last text-segment frchain.) */
extern frchainS *data0_frchainP;
extern frchainS *bss0_frchainP;
#define seg_info(S) (abort (), (segment_info_type *) 0)
#endif
#endif /* ! BFD_ASSEMBLER */
extern void subsegs_print_statistics (FILE *);
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