[deliverable/binutils-gdb.git] / gas / subsegs.c

/* subsegs.c - subsegments -
   Copyright (C) 1987, 1990, 1991, 1992, 1993, 1994
   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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/*
 * Segments & sub-segments.
 */

#include "as.h"

#include "subsegs.h"
#include "obstack.h"

frchainS *frchain_root, *frchain_now;

static struct obstack frchains;

#ifndef BFD_ASSEMBLER
#ifdef MANY_SEGMENTS
segment_info_type segment_info[SEG_MAXIMUM_ORDINAL];

#else
/* Commented in "subsegs.h". */
frchainS *data0_frchainP, *bss0_frchainP;

#endif /* MANY_SEGMENTS */
char const *const seg_name[] =
{
  "absolute",
#ifdef MANY_SEGMENTS
  "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9",
#else
  "text",
  "data",
  "bss",
#endif /* MANY_SEGMENTS */
  "unknown",
  "ASSEMBLER-INTERNAL-LOGIC-ERROR!",
  "expr",
  "debug",
  "transfert vector preload",
  "transfert vector postload",
  "register",
  "",
};				/* Used by error reporters, dumpers etc. */
#else /* BFD_ASSEMBLER */

/* Gas segment information for bfd_abs_section_ptr and
   bfd_und_section_ptr.  */
static segment_info_type *abs_seg_info;
static segment_info_type *und_seg_info;

#endif /* BFD_ASSEMBLER */

static void subseg_set_rest PARAMS ((segT, subsegT));

static fragS dummy_frag;

static frchainS absolute_frchain;
\f
void
subsegs_begin ()
{
  /* Check table(s) seg_name[], seg_N_TYPE[] is in correct order */
#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
  know (SEG_ABSOLUTE == 0);
  know (SEG_TEXT == 1);
  know (SEG_DATA == 2);
  know (SEG_BSS == 3);
  know (SEG_UNKNOWN == 4);
  know (SEG_GOOF == 5);
  know (SEG_EXPR == 6);
  know (SEG_DEBUG == 7);
  know (SEG_NTV == 8);
  know (SEG_PTV == 9);
  know (SEG_REGISTER == 10);
  know (SEG_MAXIMUM_ORDINAL == SEG_REGISTER);
#endif

  obstack_begin (&frchains, chunksize);
#if __GNUC__ >= 2
  obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1;
#endif

  frchain_root = NULL;
  frchain_now = NULL;		/* Warn new_subseg() that we are booting. */

  frag_now = &dummy_frag;

#ifndef BFD_ASSEMBLER
  now_subseg = 42;		/* Lie for 1st call to subseg_new. */
#ifdef MANY_SEGMENTS
  {
    int i;
    for (i = SEG_E0; i < SEG_UNKNOWN; i++)
      {
	subseg_set (i, 0);
	segment_info[i].frchainP = frchain_now;
      }
  }
#else
  subseg_set (SEG_DATA, 0);	/* .data 0 */
  data0_frchainP = frchain_now;

  subseg_set (SEG_BSS, 0);
  bss0_frchainP = frchain_now;

#endif /* ! MANY_SEGMENTS */
#endif /* ! BFD_ASSEMBLER */

  absolute_frchain.frch_seg = absolute_section;
  absolute_frchain.frch_subseg = 0;
  absolute_frchain.fix_root = absolute_frchain.fix_tail = 0;
  absolute_frchain.frch_frag_now = &zero_address_frag;
  absolute_frchain.frch_root = absolute_frchain.frch_last = &zero_address_frag;
}
\f
/*
 *			subseg_change()
 *
 * Change the subsegment we are in, BUT DO NOT MAKE A NEW FRAG for the
 * subsegment. If we are already in the correct subsegment, change nothing.
 * This is used eg as a worker for subseg_set [which does make a new frag_now]
 * and for changing segments after we have read the source. We construct eg
 * fixSs even after the source file is read, so we do have to keep the
 * segment context correct.
 */
void
subseg_change (seg, subseg)
     register segT seg;
     register int subseg;
{
  now_seg = seg;
  now_subseg = subseg;

  if (now_seg == absolute_section)
    return;

#ifdef BFD_ASSEMBLER
  {
    segment_info_type *seginfo;
    seginfo = (segment_info_type *) bfd_get_section_userdata (stdoutput, seg);
    if (! seginfo)
      {
	seginfo = (segment_info_type *) xmalloc (sizeof (*seginfo));
	memset ((PTR) seginfo, 0, sizeof (*seginfo));
	seginfo->fix_root = NULL;
	seginfo->fix_tail = NULL;
	seginfo->bfd_section = seg;
	seginfo->sym = 0;
	if (seg == bfd_abs_section_ptr)
	  abs_seg_info = seginfo;
	else if (seg == bfd_und_section_ptr)
	  und_seg_info = seginfo;
	else
	  bfd_set_section_userdata (stdoutput, seg, (PTR) seginfo);
      }
  }
#else
#ifdef MANY_SEGMENTS
  seg_fix_rootP = &segment_info[seg].fix_root;
  seg_fix_tailP = &segment_info[seg].fix_tail;
#else
  if (seg == SEG_DATA)
    {
      seg_fix_rootP = &data_fix_root;
      seg_fix_tailP = &data_fix_tail;
    }
  else if (seg == SEG_TEXT)
    {
      seg_fix_rootP = &text_fix_root;
      seg_fix_tailP = &text_fix_tail;
    }
  else
    {
      know (seg == SEG_BSS);
      seg_fix_rootP = &bss_fix_root;
      seg_fix_tailP = &bss_fix_tail;
    }

#endif
#endif
}
\f
static void
subseg_set_rest (seg, subseg)
     segT seg;
     subsegT subseg;
{
  long tmp;			/* JF for obstack alignment hacking */
  register frchainS *frcP;	/* crawl frchain chain */
  register frchainS **lastPP;	/* address of last pointer */
  frchainS *newP;		/* address of new frchain */
  register fragS *former_last_fragP;
  register fragS *new_fragP;

  mri_common_symbol = NULL;

  if (frag_now && frchain_now)
    frchain_now->frch_frag_now = frag_now;

  assert (frchain_now == 0
	  || now_seg == undefined_section
	  || now_seg == absolute_section
	  || frchain_now->frch_last == frag_now);

  subseg_change (seg, (int) subseg);

  if (seg == absolute_section)
    {
      frchain_now = &absolute_frchain;
      frag_now = &zero_address_frag;
      return;
    }

  assert (frchain_now == 0
	  || now_seg == undefined_section
	  || frchain_now->frch_last == frag_now);

  /*
   * Attempt to find or make a frchain for that sub seg.
   * Crawl along chain of frchainSs, begins @ frchain_root.
   * If we need to make a frchainS, link it into correct
   * position of chain rooted in frchain_root.
   */
  for (frcP = *(lastPP = &frchain_root);
       frcP && frcP->frch_seg <= seg;
       frcP = *(lastPP = &frcP->frch_next))
    {
      if (frcP->frch_seg == seg
	  && frcP->frch_subseg >= subseg)
	{
	  break;
	}
    }
  /*
   * frcP:		Address of the 1st frchainS in correct segment with
   *		frch_subseg >= subseg.
   *		We want to either use this frchainS, or we want
   *		to insert a new frchainS just before it.
   *
   *		If frcP==NULL, then we are at the end of the chain
   *		of frchainS-s. A NULL frcP means we fell off the end
   *		of the chain looking for a
   *		frch_subseg >= subseg, so we
   *		must make a new frchainS.
   *
   *		If we ever maintain a pointer to
   *		the last frchainS in the chain, we change that pointer
   *		ONLY when frcP==NULL.
   *
   * lastPP:	Address of the pointer with value frcP;
   *		Never NULL.
   *		May point to frchain_root.
   *
   */
  if (!frcP
      || (frcP->frch_seg > seg
	  || frcP->frch_subseg > subseg))	/* Kinky logic only works with 2 segments. */
    {
      /*
       * This should be the only code that creates a frchainS.
       */
      extern fragS *frag_alloc ();
      newP = (frchainS *) obstack_alloc (&frchains, sizeof (frchainS));
      newP->frch_subseg = subseg;
      newP->frch_seg = seg;
#ifdef BFD_ASSEMBLER
      newP->fix_root = NULL;
      newP->fix_tail = NULL;
#endif
      obstack_begin (&newP->frch_obstack, 5000);
#if __GNUC__ >= 2
      obstack_alignment_mask (&newP->frch_obstack) = __alignof__ (fragS) - 1;
#endif
      newP->frch_frag_now = frag_alloc (&newP->frch_obstack);
      newP->frch_frag_now->fr_type = rs_fill;

      newP->frch_root = newP->frch_last = newP->frch_frag_now;

      *lastPP = newP;
      newP->frch_next = frcP;	/* perhaps NULL */
      frcP = newP;
    }
  /*
   * Here with frcP pointing to the frchainS for subseg.
   */
  frchain_now = frcP;
  frag_now = frcP->frch_frag_now;

  assert (frchain_now->frch_last == frag_now);
}

/*
 *			subseg_set(segT, subsegT)
 *
 * If you attempt to change to the current subsegment, nothing happens.
 *
 * In:	segT, subsegT code for new subsegment.
 *	frag_now -> incomplete frag for current subsegment.
 *	If frag_now==NULL, then there is no old, incomplete frag, so
 *	the old frag is not closed off.
 *
 * Out:	now_subseg, now_seg updated.
 *	Frchain_now points to the (possibly new) struct frchain for this
 *	sub-segment.
 *	Frchain_root updated if needed.
 */

#ifndef BFD_ASSEMBLER

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  int i;

  for (i = 0; i < (int) SEG_MAXIMUM_ORDINAL; i++)
    {
      const char *s;

      s = segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#ifdef obj_segment_name
      s = obj_segment_name ((segT) i);
      if (strcmp (segname, s) == 0
	  || (segname[0] == '.'
	      && strcmp (segname + 1, s) == 0))
	{
	  subseg_set ((segT) i, subseg);
	  return (segT) i;
	}
#endif
    }

#ifdef obj_add_segment
  {
    segT new_seg;
    new_seg = obj_add_segment (segname);
    subseg_set (new_seg, subseg);
    return new_seg;
  }
#else
  as_bad ("Attempt to switch to nonexistent segment \"%s\"", segname);
  return now_seg;
#endif
}

void
subseg_set (seg, subseg)	/* begin assembly for a new sub-segment */
     register segT seg;		/* SEG_DATA or SEG_TEXT */
     register subsegT subseg;
{
#ifndef MANY_SEGMENTS
  know (seg == SEG_DATA
	|| seg == SEG_TEXT
	|| seg == SEG_BSS
	|| seg == SEG_ABSOLUTE);
#endif

  if (seg != now_seg || subseg != now_subseg)
    {				/* we just changed sub-segments */
      subseg_set_rest (seg, subseg);
    }
  mri_common_symbol = NULL;
}

#else /* BFD_ASSEMBLER */

segT
subseg_get (segname, force_new)
     const char *segname;
     int force_new;
{
  segT secptr;
  segment_info_type *seginfo;
  const char *now_seg_name = (now_seg
			      ? bfd_get_section_name (stdoutput, now_seg)
			      : 0);

  if (!force_new
      && now_seg_name
      && (now_seg_name == segname
	  || !strcmp (now_seg_name, segname)))
    return now_seg;

  if (!force_new)
    secptr = bfd_make_section_old_way (stdoutput, segname);
  else
    secptr = bfd_make_section_anyway (stdoutput, segname);

  seginfo = seg_info (secptr);
  if (! seginfo)
    {
      /* Check whether output_section is set first because secptr may
         be bfd_abs_section_ptr.  */
      if (secptr->output_section != secptr)
	secptr->output_section = secptr;
      seginfo = (segment_info_type *) xmalloc (sizeof (*seginfo));
      memset ((PTR) seginfo, 0, sizeof (*seginfo));
      seginfo->fix_root = NULL;
      seginfo->fix_tail = NULL;
      seginfo->bfd_section = secptr;
      if (secptr == bfd_abs_section_ptr)
	abs_seg_info = seginfo;
      else if (secptr == bfd_und_section_ptr)
	und_seg_info = seginfo;
      else
	bfd_set_section_userdata (stdoutput, secptr, (PTR) seginfo);
      seginfo->frchainP = NULL;
      seginfo->lineno_list_head = seginfo->lineno_list_tail = NULL;
      seginfo->sym = NULL;
      seginfo->dot = NULL;
    }
  return secptr;
}

segT
subseg_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 0);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

/* Like subseg_new, except a new section is always created, even if
   a section with that name already exists.  */
segT
subseg_force_new (segname, subseg)
     const char *segname;
     subsegT subseg;
{
  segT secptr;
  segment_info_type *seginfo;

  secptr = subseg_get (segname, 1);
  subseg_set_rest (secptr, subseg);
  seginfo = seg_info (secptr);
  if (! seginfo->frchainP)
    seginfo->frchainP = frchain_now;
  return secptr;
}

void
subseg_set (secptr, subseg)
     segT secptr;
     subsegT subseg;
{
  if (! (secptr == now_seg && subseg == now_subseg))
    subseg_set_rest (secptr, subseg);
  mri_common_symbol = NULL;
}

#ifndef obj_sec_sym_ok_for_reloc
#define obj_sec_sym_ok_for_reloc(SEC)	0
#endif

/* Get the gas information we are storing for a section.  */

segment_info_type *
seg_info (sec)
     segT sec;
{
  if (sec == bfd_abs_section_ptr)
    return abs_seg_info;
  else if (sec == bfd_und_section_ptr)
    return und_seg_info;
  else
    return (segment_info_type *) bfd_get_section_userdata (stdoutput, sec);
}

symbolS *
section_symbol (sec)
     segT sec;
{
  segment_info_type *seginfo = seg_info (sec);
  symbolS *s;

  if (seginfo == 0)
    abort ();
  if (seginfo->sym)
    return seginfo->sym;
  s = symbol_find (sec->name);
  if (!s)
    {
#ifndef EMIT_SECTION_SYMBOLS
#define EMIT_SECTION_SYMBOLS 1
#endif

      if (! EMIT_SECTION_SYMBOLS
#ifdef BFD_ASSEMBLER
	  && symbol_table_frozen
#endif
	  )
	/* Here we know it won't be going into the symbol table.  */
	s = symbol_create (sec->name, sec, 0, &zero_address_frag);
      else
	s = symbol_new (sec->name, sec, 0, &zero_address_frag);
      S_CLEAR_EXTERNAL (s);

      /* Use the BFD section symbol, if possible.  */
      if (obj_sec_sym_ok_for_reloc (sec))
	s->bsym = sec->symbol;
    }
  seginfo->sym = s;
  return s;
}

#endif /* BFD_ASSEMBLER */

/* end of subsegs.c */
Commit	Line	Data
	1	/* subsegs.c - subsegments -
	2	Copyright (C) 1987, 1990, 1991, 1992, 1993, 1994
	3	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	* Segments & sub-segments.
	23	*/
	24
	25	#include "as.h"
	26
	27	#include "subsegs.h"
	28	#include "obstack.h"
	29
	30	frchainS frchain_root, frchain_now;
	31
	32	static struct obstack frchains;
	33
	34	#ifndef BFD_ASSEMBLER
	35	#ifdef MANY_SEGMENTS
	36	segment_info_type segment_info[SEG_MAXIMUM_ORDINAL];
	37
	38	#else
	39	/* Commented in "subsegs.h". */
	40	frchainS data0_frchainP, bss0_frchainP;
	41
	42	#endif /* MANY_SEGMENTS */
	43	char const *const seg_name[] =
	44	{
	45	"absolute",
	46	#ifdef MANY_SEGMENTS
	47	"e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9",
	48	#else
	49	"text",
	50	"data",
	51	"bss",
	52	#endif /* MANY_SEGMENTS */
	53	"unknown",
	54	"ASSEMBLER-INTERNAL-LOGIC-ERROR!",
	55	"expr",
	56	"debug",
	57	"transfert vector preload",
	58	"transfert vector postload",
	59	"register",
	60	"",
	61	}; /* Used by error reporters, dumpers etc. */
	62	#else /* BFD_ASSEMBLER */
	63
	64	/* Gas segment information for bfd_abs_section_ptr and
	65	bfd_und_section_ptr. */
	66	static segment_info_type *abs_seg_info;
	67	static segment_info_type *und_seg_info;
	68
	69	#endif /* BFD_ASSEMBLER */
	70
	71	static void subseg_set_rest PARAMS ((segT, subsegT));
	72
	73	static fragS dummy_frag;
	74
	75	static frchainS absolute_frchain;
	76	\f
	77	void
	78	subsegs_begin ()
	79	{
	80	/* Check table(s) seg_name[], seg_N_TYPE[] is in correct order */
	81	#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
	82	know (SEG_ABSOLUTE == 0);
	83	know (SEG_TEXT == 1);
	84	know (SEG_DATA == 2);
	85	know (SEG_BSS == 3);
	86	know (SEG_UNKNOWN == 4);
	87	know (SEG_GOOF == 5);
	88	know (SEG_EXPR == 6);
	89	know (SEG_DEBUG == 7);
	90	know (SEG_NTV == 8);
	91	know (SEG_PTV == 9);
	92	know (SEG_REGISTER == 10);
	93	know (SEG_MAXIMUM_ORDINAL == SEG_REGISTER);
	94	#endif
	95
	96	obstack_begin (&frchains, chunksize);
	97	#if __GNUC__ >= 2
	98	obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1;
	99	#endif
	100
	101	frchain_root = NULL;
	102	frchain_now = NULL; /* Warn new_subseg() that we are booting. */
	103
	104	frag_now = &dummy_frag;
	105
	106	#ifndef BFD_ASSEMBLER
	107	now_subseg = 42; /* Lie for 1st call to subseg_new. */
	108	#ifdef MANY_SEGMENTS
	109	{
	110	int i;
	111	for (i = SEG_E0; i < SEG_UNKNOWN; i++)
	112	{
	113	subseg_set (i, 0);
	114	segment_info[i].frchainP = frchain_now;
	115	}
	116	}
	117	#else
	118	subseg_set (SEG_DATA, 0); /* .data 0 */
	119	data0_frchainP = frchain_now;
	120
	121	subseg_set (SEG_BSS, 0);
	122	bss0_frchainP = frchain_now;
	123
	124	#endif /* ! MANY_SEGMENTS */
	125	#endif /* ! BFD_ASSEMBLER */
	126
	127	absolute_frchain.frch_seg = absolute_section;
	128	absolute_frchain.frch_subseg = 0;
	129	absolute_frchain.fix_root = absolute_frchain.fix_tail = 0;
	130	absolute_frchain.frch_frag_now = &zero_address_frag;
	131	absolute_frchain.frch_root = absolute_frchain.frch_last = &zero_address_frag;
	132	}
	133	\f
	134	/*
	135	* subseg_change()
	136	*
	137	* Change the subsegment we are in, BUT DO NOT MAKE A NEW FRAG for the
	138	* subsegment. If we are already in the correct subsegment, change nothing.
	139	* This is used eg as a worker for subseg_set [which does make a new frag_now]
	140	* and for changing segments after we have read the source. We construct eg
	141	* fixSs even after the source file is read, so we do have to keep the
	142	* segment context correct.
	143	*/
	144	void
	145	subseg_change (seg, subseg)
	146	register segT seg;
	147	register int subseg;
	148	{
	149	now_seg = seg;
	150	now_subseg = subseg;
	151
	152	if (now_seg == absolute_section)
	153	return;
	154
	155	#ifdef BFD_ASSEMBLER
	156	{
	157	segment_info_type *seginfo;
	158	seginfo = (segment_info_type *) bfd_get_section_userdata (stdoutput, seg);
	159	if (! seginfo)
	160	{
	161	seginfo = (segment_info_type ) xmalloc (sizeof (seginfo));
	162	memset ((PTR) seginfo, 0, sizeof (*seginfo));
	163	seginfo->fix_root = NULL;
	164	seginfo->fix_tail = NULL;
	165	seginfo->bfd_section = seg;
	166	seginfo->sym = 0;
	167	if (seg == bfd_abs_section_ptr)
	168	abs_seg_info = seginfo;
	169	else if (seg == bfd_und_section_ptr)
	170	und_seg_info = seginfo;
	171	else
	172	bfd_set_section_userdata (stdoutput, seg, (PTR) seginfo);
	173	}
	174	}
	175	#else
	176	#ifdef MANY_SEGMENTS
	177	seg_fix_rootP = &segment_info[seg].fix_root;
	178	seg_fix_tailP = &segment_info[seg].fix_tail;
	179	#else
	180	if (seg == SEG_DATA)
	181	{
	182	seg_fix_rootP = &data_fix_root;
	183	seg_fix_tailP = &data_fix_tail;
	184	}
	185	else if (seg == SEG_TEXT)
	186	{
	187	seg_fix_rootP = &text_fix_root;
	188	seg_fix_tailP = &text_fix_tail;
	189	}
	190	else
	191	{
	192	know (seg == SEG_BSS);
	193	seg_fix_rootP = &bss_fix_root;
	194	seg_fix_tailP = &bss_fix_tail;
	195	}
	196
	197	#endif
	198	#endif
	199	}
	200	\f
	201	static void
	202	subseg_set_rest (seg, subseg)
	203	segT seg;
	204	subsegT subseg;
	205	{
	206	long tmp; /* JF for obstack alignment hacking */
	207	register frchainS frcP; / crawl frchain chain */
	208	register frchainS *lastPP; / address of last pointer */
	209	frchainS newP; / address of new frchain */
	210	register fragS *former_last_fragP;
	211	register fragS *new_fragP;
	212
	213	mri_common_symbol = NULL;
	214
	215	if (frag_now && frchain_now)
	216	frchain_now->frch_frag_now = frag_now;
	217
	218	assert (frchain_now == 0
	219	\|\| now_seg == undefined_section
	220	\|\| now_seg == absolute_section
	221	\|\| frchain_now->frch_last == frag_now);
	222
	223	subseg_change (seg, (int) subseg);
	224
	225	if (seg == absolute_section)
	226	{
	227	frchain_now = &absolute_frchain;
	228	frag_now = &zero_address_frag;
	229	return;
	230	}
	231
	232	assert (frchain_now == 0
	233	\|\| now_seg == undefined_section
	234	\|\| frchain_now->frch_last == frag_now);
	235
	236	/*
	237	* Attempt to find or make a frchain for that sub seg.
	238	* Crawl along chain of frchainSs, begins @ frchain_root.
	239	* If we need to make a frchainS, link it into correct
	240	* position of chain rooted in frchain_root.
	241	*/
	242	for (frcP = *(lastPP = &frchain_root);
	243	frcP && frcP->frch_seg <= seg;
	244	frcP = *(lastPP = &frcP->frch_next))
	245	{
	246	if (frcP->frch_seg == seg
	247	&& frcP->frch_subseg >= subseg)
	248	{
	249	break;
	250	}
	251	}
	252	/*
	253	* frcP: Address of the 1st frchainS in correct segment with
	254	* frch_subseg >= subseg.
	255	* We want to either use this frchainS, or we want
	256	* to insert a new frchainS just before it.
	257	*
	258	* If frcP==NULL, then we are at the end of the chain
	259	* of frchainS-s. A NULL frcP means we fell off the end
	260	* of the chain looking for a
	261	* frch_subseg >= subseg, so we
	262	* must make a new frchainS.
	263	*
	264	* If we ever maintain a pointer to
	265	* the last frchainS in the chain, we change that pointer
	266	* ONLY when frcP==NULL.
	267	*
	268	* lastPP: Address of the pointer with value frcP;
	269	* Never NULL.
	270	* May point to frchain_root.
	271	*
	272	*/
	273	if (!frcP
	274	\|\| (frcP->frch_seg > seg
	275	\|\| frcP->frch_subseg > subseg)) /* Kinky logic only works with 2 segments. */
	276	{
	277	/*
	278	* This should be the only code that creates a frchainS.
	279	*/
	280	extern fragS *frag_alloc ();
	281	newP = (frchainS *) obstack_alloc (&frchains, sizeof (frchainS));
	282	newP->frch_subseg = subseg;
	283	newP->frch_seg = seg;
	284	#ifdef BFD_ASSEMBLER
	285	newP->fix_root = NULL;
	286	newP->fix_tail = NULL;
	287	#endif
	288	obstack_begin (&newP->frch_obstack, 5000);
	289	#if __GNUC__ >= 2
	290	obstack_alignment_mask (&newP->frch_obstack) = __alignof__ (fragS) - 1;
	291	#endif
	292	newP->frch_frag_now = frag_alloc (&newP->frch_obstack);
	293	newP->frch_frag_now->fr_type = rs_fill;
	294
	295	newP->frch_root = newP->frch_last = newP->frch_frag_now;
	296
	297	*lastPP = newP;
	298	newP->frch_next = frcP; /* perhaps NULL */
	299	frcP = newP;
	300	}
	301	/*
	302	* Here with frcP pointing to the frchainS for subseg.
	303	*/
	304	frchain_now = frcP;
	305	frag_now = frcP->frch_frag_now;
	306
	307	assert (frchain_now->frch_last == frag_now);
	308	}
	309
	310	/*
	311	* subseg_set(segT, subsegT)
	312	*
	313	* If you attempt to change to the current subsegment, nothing happens.
	314	*
	315	* In: segT, subsegT code for new subsegment.
	316	* frag_now -> incomplete frag for current subsegment.
	317	* If frag_now==NULL, then there is no old, incomplete frag, so
	318	* the old frag is not closed off.
	319	*
	320	* Out: now_subseg, now_seg updated.
	321	* Frchain_now points to the (possibly new) struct frchain for this
	322	* sub-segment.
	323	* Frchain_root updated if needed.
	324	*/
	325
	326	#ifndef BFD_ASSEMBLER
	327
	328	segT
	329	subseg_new (segname, subseg)
	330	const char *segname;
	331	subsegT subseg;
	332	{
	333	int i;
	334
	335	for (i = 0; i < (int) SEG_MAXIMUM_ORDINAL; i++)
	336	{
	337	const char *s;
	338
	339	s = segment_name ((segT) i);
	340	if (strcmp (segname, s) == 0
	341	\|\| (segname[0] == '.'
	342	&& strcmp (segname + 1, s) == 0))
	343	{
	344	subseg_set ((segT) i, subseg);
	345	return (segT) i;
	346	}
	347	#ifdef obj_segment_name
	348	s = obj_segment_name ((segT) i);
	349	if (strcmp (segname, s) == 0
	350	\|\| (segname[0] == '.'
	351	&& strcmp (segname + 1, s) == 0))
	352	{
	353	subseg_set ((segT) i, subseg);
	354	return (segT) i;
	355	}
	356	#endif
	357	}
	358
	359	#ifdef obj_add_segment
	360	{
	361	segT new_seg;
	362	new_seg = obj_add_segment (segname);
	363	subseg_set (new_seg, subseg);
	364	return new_seg;
	365	}
	366	#else
	367	as_bad ("Attempt to switch to nonexistent segment \"%s\"", segname);
	368	return now_seg;
	369	#endif
	370	}
	371
	372	void
	373	subseg_set (seg, subseg) /* begin assembly for a new sub-segment */
	374	register segT seg; /* SEG_DATA or SEG_TEXT */
	375	register subsegT subseg;
	376	{
	377	#ifndef MANY_SEGMENTS
	378	know (seg == SEG_DATA
	379	\|\| seg == SEG_TEXT
	380	\|\| seg == SEG_BSS
	381	\|\| seg == SEG_ABSOLUTE);
	382	#endif
	383
	384	if (seg != now_seg \|\| subseg != now_subseg)
	385	{ /* we just changed sub-segments */
	386	subseg_set_rest (seg, subseg);
	387	}
	388	mri_common_symbol = NULL;
	389	}
	390
	391	#else /* BFD_ASSEMBLER */
	392
	393	segT
	394	subseg_get (segname, force_new)
	395	const char *segname;
	396	int force_new;
	397	{
	398	segT secptr;
	399	segment_info_type *seginfo;
	400	const char *now_seg_name = (now_seg
	401	? bfd_get_section_name (stdoutput, now_seg)
	402	: 0);
	403
	404	if (!force_new
	405	&& now_seg_name
	406	&& (now_seg_name == segname
	407	\|\| !strcmp (now_seg_name, segname)))
	408	return now_seg;
	409
	410	if (!force_new)
	411	secptr = bfd_make_section_old_way (stdoutput, segname);
	412	else
	413	secptr = bfd_make_section_anyway (stdoutput, segname);
	414
	415	seginfo = seg_info (secptr);
	416	if (! seginfo)
	417	{
	418	/* Check whether output_section is set first because secptr may
	419	be bfd_abs_section_ptr. */
	420	if (secptr->output_section != secptr)
	421	secptr->output_section = secptr;
	422	seginfo = (segment_info_type ) xmalloc (sizeof (seginfo));
	423	memset ((PTR) seginfo, 0, sizeof (*seginfo));
	424	seginfo->fix_root = NULL;
	425	seginfo->fix_tail = NULL;
	426	seginfo->bfd_section = secptr;
	427	if (secptr == bfd_abs_section_ptr)
	428	abs_seg_info = seginfo;
	429	else if (secptr == bfd_und_section_ptr)
	430	und_seg_info = seginfo;
	431	else
	432	bfd_set_section_userdata (stdoutput, secptr, (PTR) seginfo);
	433	seginfo->frchainP = NULL;
	434	seginfo->lineno_list_head = seginfo->lineno_list_tail = NULL;
	435	seginfo->sym = NULL;
	436	seginfo->dot = NULL;
	437	}
	438	return secptr;
	439	}
	440
	441	segT
	442	subseg_new (segname, subseg)
	443	const char *segname;
	444	subsegT subseg;
	445	{
	446	segT secptr;
	447	segment_info_type *seginfo;
	448
	449	secptr = subseg_get (segname, 0);
	450	subseg_set_rest (secptr, subseg);
	451	seginfo = seg_info (secptr);
	452	if (! seginfo->frchainP)
	453	seginfo->frchainP = frchain_now;
	454	return secptr;
	455	}
	456
	457	/* Like subseg_new, except a new section is always created, even if
	458	a section with that name already exists. */
	459	segT
	460	subseg_force_new (segname, subseg)
	461	const char *segname;
	462	subsegT subseg;
	463	{
	464	segT secptr;
	465	segment_info_type *seginfo;
	466
	467	secptr = subseg_get (segname, 1);
	468	subseg_set_rest (secptr, subseg);
	469	seginfo = seg_info (secptr);
	470	if (! seginfo->frchainP)
	471	seginfo->frchainP = frchain_now;
	472	return secptr;
	473	}
	474
	475	void
	476	subseg_set (secptr, subseg)
	477	segT secptr;
	478	subsegT subseg;
	479	{
	480	if (! (secptr == now_seg && subseg == now_subseg))
	481	subseg_set_rest (secptr, subseg);
	482	mri_common_symbol = NULL;
	483	}
	484
	485	#ifndef obj_sec_sym_ok_for_reloc
	486	#define obj_sec_sym_ok_for_reloc(SEC) 0
	487	#endif
	488
	489	/* Get the gas information we are storing for a section. */
	490
	491	segment_info_type *
	492	seg_info (sec)
	493	segT sec;
	494	{
	495	if (sec == bfd_abs_section_ptr)
	496	return abs_seg_info;
	497	else if (sec == bfd_und_section_ptr)
	498	return und_seg_info;
	499	else
	500	return (segment_info_type *) bfd_get_section_userdata (stdoutput, sec);
	501	}
	502
	503	symbolS *
	504	section_symbol (sec)
	505	segT sec;
	506	{
	507	segment_info_type *seginfo = seg_info (sec);
	508	symbolS *s;
	509
	510	if (seginfo == 0)
	511	abort ();
	512	if (seginfo->sym)
	513	return seginfo->sym;
	514	s = symbol_find (sec->name);
	515	if (!s)
	516	{
	517	#ifndef EMIT_SECTION_SYMBOLS
	518	#define EMIT_SECTION_SYMBOLS 1
	519	#endif
	520
	521	if (! EMIT_SECTION_SYMBOLS
	522	#ifdef BFD_ASSEMBLER
	523	&& symbol_table_frozen
	524	#endif
	525	)
	526	/* Here we know it won't be going into the symbol table. */
	527	s = symbol_create (sec->name, sec, 0, &zero_address_frag);
	528	else
	529	s = symbol_new (sec->name, sec, 0, &zero_address_frag);
	530	S_CLEAR_EXTERNAL (s);
	531
	532	/* Use the BFD section symbol, if possible. */
	533	if (obj_sec_sym_ok_for_reloc (sec))
	534	s->bsym = sec->symbol;
	535	}
	536	seginfo->sym = s;
	537	return s;
	538	}
	539
	540	#endif /* BFD_ASSEMBLER */
	541
	542	/* end of subsegs.c */