297 lines
7.9 KiB
C
297 lines
7.9 KiB
C
/* frags.c - manage frags -
|
||
|
||
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. */
|
||
|
||
#ifndef lint
|
||
static char rcsid[] = "$Id$";
|
||
#endif
|
||
|
||
#include "as.h"
|
||
#include "subsegs.h"
|
||
#include "obstack.h"
|
||
|
||
struct obstack frags; /* All, and only, frags live here. */
|
||
|
||
fragS zero_address_frag = {
|
||
0, /* fr_address */
|
||
NULL, /* fr_next */
|
||
0, /* fr_fix */
|
||
0, /* fr_var */
|
||
0, /* fr_symbol */
|
||
0, /* fr_offset */
|
||
NULL, /* fr_opcode */
|
||
rs_fill, /* fr_type */
|
||
0, /* fr_subtype */
|
||
0, /* fr_pcrel_adjust */
|
||
0, /* fr_bsr */
|
||
0 /* fr_literal[0] */
|
||
};
|
||
|
||
fragS bss_address_frag = {
|
||
0, /* fr_address. Gets filled in to make up
|
||
sy_value-s. */
|
||
NULL, /* fr_next */
|
||
0, /* fr_fix */
|
||
0, /* fr_var */
|
||
0, /* fr_symbol */
|
||
0, /* fr_offset */
|
||
NULL, /* fr_opcode */
|
||
rs_fill, /* fr_type */
|
||
0, /* fr_subtype */
|
||
0, /* fr_pcrel_adjust */
|
||
0, /* fr_bsr */
|
||
0 /* fr_literal[0] */
|
||
};
|
||
|
||
/*
|
||
* frag_grow()
|
||
*
|
||
* Internal.
|
||
* Try to augment current frag by nchars chars.
|
||
* If there is no room, close of the current frag with a ".fill 0"
|
||
* and begin a new frag. Unless the new frag has nchars chars available
|
||
* do not return. Do not set up any fields of *now_frag.
|
||
*/
|
||
static void frag_grow(nchars)
|
||
unsigned int nchars;
|
||
{
|
||
if (obstack_room (&frags) < nchars) {
|
||
unsigned int n,oldn;
|
||
long oldc;
|
||
|
||
frag_wane(frag_now);
|
||
frag_new(0);
|
||
oldn=(unsigned)-1;
|
||
oldc=frags.chunk_size;
|
||
frags.chunk_size=2*nchars;
|
||
while ((n=obstack_room(&frags))<nchars && n<oldn) {
|
||
frag_wane(frag_now);
|
||
frag_new(0);
|
||
oldn=n;
|
||
}
|
||
frags.chunk_size=oldc;
|
||
}
|
||
if (obstack_room (&frags) < nchars)
|
||
as_fatal("Can't extend frag %d. chars", nchars);
|
||
} /* frag_grow() */
|
||
|
||
/*
|
||
* frag_new()
|
||
*
|
||
* Call this to close off a completed frag, and start up a new (empty)
|
||
* frag, in the same subsegment as the old frag.
|
||
* [frchain_now remains the same but frag_now is updated.]
|
||
* Because this calculates the correct value of fr_fix by
|
||
* looking at the obstack 'frags', it needs to know how many
|
||
* characters at the end of the old frag belong to (the maximal)
|
||
* fr_var: the rest must belong to fr_fix.
|
||
* It doesn't actually set up the old frag's fr_var: you may have
|
||
* set fr_var == 1, but allocated 10 chars to the end of the frag:
|
||
* in this case you pass old_frags_var_max_size == 10.
|
||
*
|
||
* Make a new frag, initialising some components. Link new frag at end
|
||
* of frchain_now.
|
||
*/
|
||
void frag_new(old_frags_var_max_size)
|
||
int old_frags_var_max_size; /* Number of chars (already allocated on
|
||
obstack frags) */
|
||
/* in variable_length part of frag. */
|
||
{
|
||
register fragS * former_last_fragP;
|
||
/* char *throw_away_pointer; JF unused */
|
||
register frchainS * frchP;
|
||
long tmp; /* JF */
|
||
|
||
frag_now->fr_fix = (char *) (obstack_next_free (&frags)) -
|
||
(frag_now->fr_literal) - old_frags_var_max_size;
|
||
/* Fix up old frag's fr_fix. */
|
||
|
||
obstack_finish (&frags);
|
||
/* This will align the obstack so the */
|
||
/* next struct we allocate on it will */
|
||
/* begin at a correct boundary. */
|
||
frchP = frchain_now;
|
||
know (frchP);
|
||
former_last_fragP = frchP->frch_last;
|
||
know (former_last_fragP);
|
||
know (former_last_fragP == frag_now);
|
||
obstack_blank (&frags, SIZEOF_STRUCT_FRAG);
|
||
/* We expect this will begin at a correct */
|
||
/* boundary for a struct. */
|
||
tmp=obstack_alignment_mask(&frags);
|
||
obstack_alignment_mask(&frags)=0; /* Turn off alignment */
|
||
/* If we ever hit a machine
|
||
where strings must be
|
||
aligned, we Lose Big */
|
||
frag_now=(fragS *)obstack_finish(&frags);
|
||
obstack_alignment_mask(&frags)=tmp; /* Restore alignment */
|
||
|
||
/* Just in case we don't get zero'd bytes */
|
||
memset(frag_now, '\0', SIZEOF_STRUCT_FRAG);
|
||
|
||
/* obstack_unaligned_done (&frags, &frag_now); */
|
||
/* know (frags.obstack_c_next_free == frag_now->fr_literal); */
|
||
/* Generally, frag_now->points to an */
|
||
/* address rounded up to next alignment. */
|
||
/* However, characters will add to obstack */
|
||
/* frags IMMEDIATELY after the struct frag, */
|
||
/* even if they are not starting at an */
|
||
/* alignment address. */
|
||
former_last_fragP->fr_next = frag_now;
|
||
frchP->frch_last = frag_now;
|
||
|
||
#ifndef NO_LISTING
|
||
{
|
||
extern struct list_info_struct *listing_tail;
|
||
frag_now->line = listing_tail;
|
||
}
|
||
#endif
|
||
|
||
frag_now->fr_next = NULL;
|
||
} /* frag_new() */
|
||
|
||
/*
|
||
* frag_more()
|
||
*
|
||
* Start a new frag unless we have n more chars of room in the current frag.
|
||
* Close off the old frag with a .fill 0.
|
||
*
|
||
* Return the address of the 1st char to write into. Advance
|
||
* frag_now_growth past the new chars.
|
||
*/
|
||
|
||
char *frag_more (nchars)
|
||
int nchars;
|
||
{
|
||
register char *retval;
|
||
|
||
frag_grow (nchars);
|
||
retval = obstack_next_free (&frags);
|
||
obstack_blank_fast (&frags, nchars);
|
||
return (retval);
|
||
} /* frag_more() */
|
||
|
||
/*
|
||
* frag_var()
|
||
*
|
||
* Start a new frag unless we have max_chars more chars of room in the current frag.
|
||
* Close off the old frag with a .fill 0.
|
||
*
|
||
* Set up a machine_dependent relaxable frag, then start a new frag.
|
||
* Return the address of the 1st char of the var part of the old frag
|
||
* to write into.
|
||
*/
|
||
|
||
char *frag_var(type, max_chars, var, subtype, symbol, offset, opcode)
|
||
relax_stateT type;
|
||
int max_chars;
|
||
int var;
|
||
relax_substateT subtype;
|
||
symbolS *symbol;
|
||
long offset;
|
||
char *opcode;
|
||
{
|
||
register char *retval;
|
||
|
||
frag_grow (max_chars);
|
||
retval = obstack_next_free (&frags);
|
||
obstack_blank_fast (&frags, max_chars);
|
||
frag_now->fr_var = var;
|
||
frag_now->fr_type = type;
|
||
frag_now->fr_subtype = subtype;
|
||
frag_now->fr_symbol = symbol;
|
||
frag_now->fr_offset = offset;
|
||
frag_now->fr_opcode = opcode;
|
||
/* default these to zero. */
|
||
frag_now->fr_pcrel_adjust = 0;
|
||
frag_now->fr_bsr = 0;
|
||
frag_new (max_chars);
|
||
return (retval);
|
||
} /* frag_var() */
|
||
|
||
/*
|
||
* frag_variant()
|
||
*
|
||
* OVE: This variant of frag_var assumes that space for the tail has been
|
||
* allocated by caller.
|
||
* No call to frag_grow is done.
|
||
* Two new arguments have been added.
|
||
*/
|
||
|
||
char *frag_variant(type, max_chars, var, subtype, symbol, offset, opcode, pcrel_adjust,bsr)
|
||
relax_stateT type;
|
||
int max_chars;
|
||
int var;
|
||
relax_substateT subtype;
|
||
symbolS *symbol;
|
||
long offset;
|
||
char *opcode;
|
||
int pcrel_adjust;
|
||
char bsr;
|
||
{
|
||
register char *retval;
|
||
|
||
/* frag_grow (max_chars); */
|
||
retval = obstack_next_free (&frags);
|
||
/* obstack_blank_fast (&frags, max_chars); */ /* OVE: so far the only diff */
|
||
frag_now->fr_var = var;
|
||
frag_now->fr_type = type;
|
||
frag_now->fr_subtype = subtype;
|
||
frag_now->fr_symbol = symbol;
|
||
frag_now->fr_offset = offset;
|
||
frag_now->fr_opcode = opcode;
|
||
frag_now->fr_pcrel_adjust = pcrel_adjust;
|
||
frag_now->fr_bsr = bsr;
|
||
frag_new(max_chars);
|
||
return(retval);
|
||
} /* frag_variant() */
|
||
|
||
/*
|
||
* frag_wane()
|
||
*
|
||
* Reduce the variable end of a frag to a harmless state.
|
||
*/
|
||
void frag_wane(fragP)
|
||
register fragS * fragP;
|
||
{
|
||
fragP->fr_type = rs_fill;
|
||
fragP->fr_offset = 0;
|
||
fragP->fr_var = 0;
|
||
}
|
||
|
||
/*
|
||
* frag_align()
|
||
*
|
||
* Make a frag for ".align foo,bar". Call is "frag_align (foo,bar);".
|
||
* Foo & bar are absolute integers.
|
||
*
|
||
* Call to close off the current frag with a ".align", then start a new
|
||
* (so far empty) frag, in the same subsegment as the last frag.
|
||
*/
|
||
|
||
void frag_align(alignment, fill_character)
|
||
int alignment;
|
||
int fill_character;
|
||
{
|
||
*(frag_var (rs_align, 1, 1, (relax_substateT)0, (symbolS *)0,
|
||
(long)alignment, (char *)0)) = fill_character;
|
||
} /* frag_align() */
|
||
|
||
/* end of frags.c */
|