mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-29 12:03:03 +00:00
314 lines
8.9 KiB
C
314 lines
8.9 KiB
C
/* subsegs.c - subsegments -
|
||
Copyright (C) 1987, 1990, 1991, 1992 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||
|
||
/*
|
||
* Segments & sub-segments.
|
||
*/
|
||
|
||
#ifndef lint
|
||
static char rcsid[] = "$Id$";
|
||
#endif
|
||
|
||
#include "as.h"
|
||
|
||
#include "subsegs.h"
|
||
#include "obstack.h"
|
||
|
||
#ifdef MANY_SEGMENTS
|
||
segment_info_type segment_info[SEG_MAXIMUM_ORDINAL];
|
||
|
||
frchainS* frchain_root,
|
||
* frchain_now;
|
||
|
||
#else
|
||
frchainS* frchain_root,
|
||
* frchain_now, /* Commented in "subsegs.h". */
|
||
* data0_frchainP;
|
||
|
||
#endif
|
||
char * const /* in: segT out: char* */
|
||
seg_name[] = {
|
||
"absolute",
|
||
#ifdef MANY_SEGMENTS
|
||
"e0","e1","e2","e3","e4","e5","e6","e7","e8","e9",
|
||
#else
|
||
"text",
|
||
"data",
|
||
"bss",
|
||
#endif
|
||
"unknown",
|
||
"absent",
|
||
"pass1",
|
||
"ASSEMBLER-INTERNAL-LOGIC-ERROR!",
|
||
"bignum/flonum",
|
||
"difference",
|
||
"debug",
|
||
"transfert vector preload",
|
||
"transfert vector postload",
|
||
"register",
|
||
"",
|
||
}; /* Used by error reporters, dumpers etc. */
|
||
|
||
|
||
void
|
||
subsegs_begin()
|
||
{
|
||
/* Check table(s) seg_name[], seg_N_TYPE[] is in correct order */
|
||
#ifdef MANY_SEGMENTS
|
||
#else
|
||
know(SEG_ABSOLUTE == 0);
|
||
know(SEG_TEXT == 1);
|
||
know(SEG_DATA == 2);
|
||
know(SEG_BSS == 3);
|
||
know(SEG_UNKNOWN == 4);
|
||
know(SEG_ABSENT == 5);
|
||
know(SEG_PASS1 == 6);
|
||
know(SEG_GOOF == 7);
|
||
know(SEG_BIG == 8);
|
||
know(SEG_DIFFERENCE == 9);
|
||
know(SEG_DEBUG == 10);
|
||
know(SEG_NTV == 11);
|
||
know(SEG_PTV == 12);
|
||
know(SEG_REGISTER == 13);
|
||
know(SEG_MAXIMUM_ORDINAL == SEG_REGISTER );
|
||
/* know(segment_name(SEG_MAXIMUM_ORDINAL + 1)[0] == 0);*/
|
||
#endif
|
||
|
||
obstack_begin(&frags, 5000);
|
||
frchain_root = NULL;
|
||
frchain_now = NULL; /* Warn new_subseg() that we are booting. */
|
||
/* Fake up 1st frag. */
|
||
/* It won't be used=> is ok if obstack... */
|
||
/* pads the end of it for alignment. */
|
||
frag_now=(fragS *)obstack_alloc(&frags,SIZEOF_STRUCT_FRAG);
|
||
memset(frag_now, SIZEOF_STRUCT_FRAG, 0);
|
||
/* This 1st frag will not be in any frchain. */
|
||
/* We simply give subseg_new somewhere to scribble. */
|
||
now_subseg = 42; /* Lie for 1st call to subseg_new. */
|
||
#ifdef MANY_SEGMENTS
|
||
{
|
||
int i;
|
||
for (i = SEG_E0; i < SEG_UNKNOWN; i++) {
|
||
subseg_new(i, 0);
|
||
segment_info[i].frchainP = frchain_now;
|
||
}
|
||
}
|
||
#else
|
||
subseg_new(SEG_DATA, 0); /* .data 0 */
|
||
data0_frchainP = frchain_now;
|
||
#endif
|
||
|
||
}
|
||
|
||
/*
|
||
* 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_new [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;
|
||
know(SEG_NORMAL(seg));
|
||
#ifdef MANY_SEGMENTS
|
||
seg_fix_rootP = &segment_info[seg].fix_root;
|
||
seg_fix_tailP = &segment_info[seg].fix_tail;
|
||
#else
|
||
switch (seg) {
|
||
case SEG_DATA:
|
||
seg_fix_rootP = &data_fix_root;
|
||
seg_fix_tailP = &data_fix_tail;
|
||
break;
|
||
case SEG_TEXT:
|
||
seg_fix_rootP = &text_fix_root;
|
||
seg_fix_tailP = &text_fix_tail;
|
||
break;
|
||
case SEG_BSS:
|
||
seg_fix_rootP = &bss_fix_root;
|
||
seg_fix_tailP = &bss_fix_tail;
|
||
break;
|
||
}
|
||
#endif
|
||
}
|
||
|
||
/*
|
||
* subseg_new()
|
||
*
|
||
* 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.
|
||
*/
|
||
|
||
void
|
||
subseg_new (seg, subseg) /* begin assembly for a new sub-segment */
|
||
register segT seg; /* SEG_DATA or SEG_TEXT */
|
||
register subsegT subseg;
|
||
{
|
||
long tmp; /* JF for obstack alignment hacking */
|
||
know(SEG_NORMAL(seg));
|
||
if (seg != now_seg || subseg != now_subseg)
|
||
{ /* we just changed sub-segments */
|
||
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;
|
||
|
||
if (frag_now) /* If not bootstrapping. */
|
||
{
|
||
frag_now->fr_fix = obstack_next_free(& frags) - frag_now->fr_literal;
|
||
frag_wane(frag_now); /* Close off any frag in old subseg. */
|
||
}
|
||
/*
|
||
* It would be nice to keep an obstack for each subsegment, if we swap
|
||
* subsegments a lot. Hence we would have much fewer frag_wanes().
|
||
*/
|
||
{
|
||
|
||
obstack_finish( &frags);
|
||
/*
|
||
* If we don't do the above, the next object we put on obstack frags
|
||
* will appear to start at the fr_literal of the current frag.
|
||
* Also, above ensures that the next object will begin on a
|
||
* address that is aligned correctly for the engine that runs
|
||
* this program.
|
||
*/
|
||
}
|
||
subseg_change (seg, (int)subseg);
|
||
/*
|
||
* 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
|
||
&& (int)(frcP->frch_seg) <= (int)seg;
|
||
frcP = * ( lastPP = & frcP->frch_next)
|
||
)
|
||
{
|
||
if ( (int)(frcP->frch_seg) == (int)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
|
||
|| ( (int)(frcP->frch_seg) > (int)seg
|
||
|| frcP->frch_subseg > subseg)) /* Kinky logic only works with 2 segments. */
|
||
{
|
||
/*
|
||
* This should be the only code that creates a frchainS.
|
||
*/
|
||
newP=(frchainS *)obstack_alloc(&frags,sizeof(frchainS));
|
||
memset(newP, sizeof(frchainS), 0);
|
||
/* This begines on a good boundary */
|
||
/* because a obstack_done() preceeded it. */
|
||
/* It implies an obstack_done(), so we */
|
||
/* expect the next object allocated to */
|
||
/* begin on a correct boundary. */
|
||
*lastPP = newP;
|
||
newP->frch_next = frcP; /* perhaps NULL */
|
||
(frcP = newP)->frch_subseg = subseg;
|
||
newP->frch_seg = seg;
|
||
newP->frch_last = NULL;
|
||
}
|
||
/*
|
||
* Here with frcP->ing to the frchainS for subseg.
|
||
*/
|
||
frchain_now = frcP;
|
||
/*
|
||
* Make a fresh frag for the subsegment.
|
||
*/
|
||
/* We expect this to happen on a correct */
|
||
/* boundary since it was proceeded by a */
|
||
/* obstack_done(). */
|
||
tmp=obstack_alignment_mask(&frags); /* JF disable alignment */
|
||
obstack_alignment_mask(&frags)=0;
|
||
frag_now=(fragS *)obstack_alloc(&frags,SIZEOF_STRUCT_FRAG);
|
||
obstack_alignment_mask(&frags)=tmp;
|
||
/* know(frags.obstack_c_next_free == frag_now->fr_literal); */
|
||
/* But we want any more chars to come */
|
||
/* immediately after the structure we just made. */
|
||
new_fragP = frag_now;
|
||
new_fragP->fr_next = NULL;
|
||
/*
|
||
* Append new frag to current frchain.
|
||
*/
|
||
former_last_fragP = frcP->frch_last;
|
||
if (former_last_fragP)
|
||
{
|
||
know( former_last_fragP->fr_next == NULL );
|
||
know( frchain_now->frch_root );
|
||
former_last_fragP->fr_next = new_fragP;
|
||
}
|
||
else
|
||
{
|
||
frcP->frch_root = new_fragP;
|
||
}
|
||
frcP->frch_last = new_fragP;
|
||
} /* if (changing subsegments) */
|
||
} /* subseg_new() */
|
||
|
||
/*
|
||
* Local Variables:
|
||
* comment-column: 0
|
||
* fill-column: 131
|
||
* End:
|
||
*/
|
||
|
||
/* end of subsegs.c */
|