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/* subsegs.h -> subsegs.c

   Copyright 1987, 1992, 1993, 1994, 1995, 1996, 1998, 2000, 2003, 2005,

   2006, 2007 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 3, 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 frch_cfi_data;

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 */

  subsegT frch_subseg;          /* subsegment number of this chain */

  fixS *fix_root;               /* Root of fixups for this subsegment.  */

  fixS *fix_tail;               /* Last fixup for this subsegment.  */

  struct obstack frch_obstack;  /* for objects in this frag chain */

  fragS *frch_frag_now;         /* frag_now for this subsegment */

  struct frch_cfi_data *frch_cfi_data;

};

typedef struct frchain frchainS;

/* 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.  This is only valid after the frchains

     are run together.  */

  fixS *fix_root;

  fixS *fix_tail;

  symbolS *dot;

  struct lineno_list *lineno_list_head;

  struct lineno_list *lineno_list_tail;

  /* 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;

  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;

#define seg_info(sec) \

  ((segment_info_type *) bfd_get_section_userdata (stdoutput, sec))

extern symbolS *section_symbol (segT);

extern void subsegs_print_statistics (FILE *);